St Catherine's Castle 16th century blockhouse, 19th century gun battery and 20th century gun emplacement at St Catherine's Point


Heritage Category:
Scheduled Monument
List Entry Number:
Date first listed:
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The building or site itself may lie within the boundary of more than one authority.

Cornwall (Unitary Authority)
National Grid Reference:
SX 11879 50938

Reasons for Designation

Blockhouses are small strongly-built defensive structures, built from the late 14th to mid 17th centuries and designed to house guns and protect the gunners and ammunition from attack, often while being located in a forward or exposed position. Blockhouses vary considerably in form, construction and ground plan but were typically sited as forward defences to cover anchorages, harbours, other defences and their approaches. They include a single free-standing structure, usually built of stone, incorporating a gun platform. The gun platform may be situated in a tower or a bastion. Accommodation for the gunners or look-out troops was of limited extent if provided at all. Twenty-seven blockhouses with surviving remains are recorded nationally, providing information on the developing fortification methods and military strategies during the later medieval and early post-medieval periods.

The blockhouse at St Catherine's Castle survives well. Despite minor modifications, the original built structure remains almost intact and retains clear evidence for its former internal layout and fittings, together with its manner of armament. Its reinforcement by the adjacent bastioned curtain wall is unusual. The historical context in which the blockhouse was built is well-documented and the monument's design is of special interest, being an immediate precursor to the building of Henry VIII's principal coastal fortifications. The depiction of the blockhouse as half-built on the 1540 map provides unusual confirmation for its date of construction and emphasises its role as part of a group of fortifications along the coast. Its proximity to the surviving earlier blockhouses across the Fowey estuary and the successive alterations arising from its re-armament as a gun battery during the Crimean War and World War II demonstrate well the developments in military architecture, technology and defensive tactics since the medieval period. At each stage the monument functioned as an integral part of a wider defensive network, underlining the continued importance of this monument in the nation's defence.


The monument includes an early 16th century blockhouse and bastioned curtain wall on the tip of a rocky headland, St Catherine's Point, at the entrance to the River Fowey estuary on the south coast of Cornwall. The curtilage of the blockhouse, as defined by its curtain wall, was refurbished in 1855 to form a gun battery during the Crimean War. After serving as a practice battery in the later 19th century, it was again modified and re-armed in 1940 as an emplacement in a more extensive World War II gun battery occupying St Catherine's Point. The blockhouse, curtain wall and later battery are Listed Grade II* and are in the care of the Secretary of State. The blockhouse was built between 1538 and 1540 during the reign of Henry VIII to strengthen the defences of the Fowey estuary as a preliminary response to heightened threats of attack from France and Spain in the immediate aftermath of the Reformation in England. It survives with a small blockhouse building on the tip of the headland's ridge. A north east - south west curtain wall extends down both slopes from the rear of the blockhouse and incorporates a small subrectangular bastion beside the blockhouse. The curtain wall terminates at precipitous cliffs at each end, cutting off a near semicircular area of c.500 sq m above the cliffs at the end of the headland. The blockhouse building has a D-shaped plan and is situated on the highest point within the curtain wall, allowing its curved wall an uninterrupted prospect up the estuary to the north east, and extending round, across the estuary mouth to the east, to face southern aspects out to sea. It was built on a prepared platform levelled into the rock, giving its straight north west wall a rock-cut face to first floor level. The blockhouse is built of slaty rubble laid to course. Its walls, up to 1.35m thick, rise through two floors and define an internal area measuring 5m north east - south west, along the straight rear wall, by up to 4.4m north west - south east, from the rear wall to the apex of the curve. The ground floor entrance faces north east and has a pointed arch framed in white freestone, chamfered along its outer edges and measuring 1.98m high by 0.89m wide. Three almost semicircular gun ports pierce the base of the ground floor wall, facing north east, ESE and SSE. The north east and ESE ports are 1.2m wide and 0.9m high on the outer face while the SSE port was larger, 1.6m wide and 0.93m high, and is now blocked. The gun ports have short outer splays and long barrel-vaulted inner splays: each inner splay and its vault is unique, ranging from 1m wide to 2.55m wide on the inner face, reflecting ad hoc solutions to supporting the wall above. A tall narrow fireplace was provided in the south west wall, rising to a chimney in the wall thickness. The rock-cut north west wall on the ground floor contains a recessed wall slot for a small guard chamber immediately within the entrance. This chamber extended 2.15m back from the entrance and was 1.75m wide, shown by wall footings visible in the earth floor on the opposite side of the entrance; joist slots in the rock face show its ceiling was 2.27m high. Higher joist slots, in the masonry above the rock-cut face, are for the first floor at 2.9m above the present ground floor surface; its floor slot is visible across the masonry of the south west wall. The first floor has five narrow windows with semicircular heads: two face north east, two SSW and one faces ESE. The north east window above the entrance is largely blocked, with a later brick-arched oven built into the lower blocking and itself now blocked. Behind the windows are long inner splays, much higher than the outer window apertures, with barrel-vaults truncated by flat lintel slabs inserted in a later rebuild and their bases 0.5m-0.8m above the upper floor level. The enlarged vaults behind these windows would enable their use as lookout and small-arms positions. To the right of the first floor ESE window, and also facing ESE, is a larger gun port, similar to those on the ground floor, with a deep barrel-vaulted inner splay and its base at the upper floor level. Another gun port, now filled by several phases of blocking and wall rebuild, is visible in the first floor masonry of the north west wall, above the rock-cut face. That gun port has a landward line of fire along the adjoining spine of the headland. In the west corner, a winder stair ascends from the first floor to a former parapet walk and was lit by two narrow slit windows, both now blocked. Beyond the blockhouse, a short length of curtain wall, 2m-2.5m high, extends south west from beside the blockhouse's west corner to the cliff edge, its upper edge stepped as it descends the slope. The bulk of the curtain wall crosses the much longer steep slope north east from the blockhouse. Adjoining the blockhouse itself, this wall defines a small sub-rectangular bastion projecting north west from the wall-line of the curtain and the blockhouse rear. The bastion has straight sides and a curved outer wall, 0.75m thick, pierced by two small inwardly-splayed musketry slits. The bastion is up to 5.75m north east - south west by 3.2m north west - south east internally. Within its south west wall, an exposed steep rock face has a narrow cut shelf and several hollows, denoting former staging erected beside the rear of the blockhouse. From the bastion, the curtain wall descends north east in a straight line to the cliff edge. This wall, up to 3m high and 0.8m wide, also has a stepped upper edge and is pierced by ten more musketry slits. A broad gateway through the curtain wall is located close to the cliff edge and measures 2.16m wide and 2.5m high, spanned by two flat granite lintel slabs. Its sides are faced by neat granite quoins which end slightly short of the lintel, suggesting the lintel slabs have been raised after original construction. Within the curtilage defined by the curtain wall and the cliff edge, later modifications mask or remove other features pertaining to the 16th century blockhouse. East of the blockhouse, a platform was levelled into the rock at the tip of the headland, 8m below the level of the blockhouse. The platform now supports features of the 19th-20th century reuse. However, walling shown at this location on an early 18th century engraving indicates that the platform itself has a much earlier origin. The musketry slits in the curtain wall show that the original route from the entrance to the blockhouse followed the inner face of that wall. Its lower slope course has been removed by the rock-cut insertion of a 19th century magazine beside the entrance, also blocking the lower four musketry slits in the curtain wall. Contemporary records give the building of this blockhouse as in the charge of Thomas Treffry, a prominent landowner of Fowey, who went on to supervise the building of Pendennis and St Mawes Castles on the River Fal estuary from 1540 in the main phase of Henry VIII's strengthening of the nation's coastal defences. This blockhouse replaced two much earlier blockhouses a short distance up the estuary on opposite banks at Fowey and Polruan, both of which still survive. An extant map of the south west English coastline drawn in summer 1540 depicts the blockhouse in this monument as `half-made' and those earlier blockhouses as `decayed'. By 1684, the burgesses of Fowey reported the blockhouse in this monument also as decayed, but a report on the town's defences in 1786 indicates that it housed six cannon. In 1815, after the Napoleonic Wars, all of the gun batteries covering the entrance to the estuary were abandoned. Major refurbishment of St Catherine's Castle was undertaken in 1855, during the Crimean War. A battery for two guns was built on the seaward edge of the lower levelled platform, below and east of the blockhouse, and a magazine was built into the rock beside the curtain wall entrance. The battery's two adjacent emplacements are accommodated behind a continuous built parapet of mortared rubble capped by iron-cramped granite coping, bevelled to the outer side. The parapet is 1.53m wide and rises to 1.46m high along its inner edge. Within the part-circular recesses at the rear of the parapet, each emplacement has two concentric iron gun carriage rails, called racers, set in granite beds. The outer and inner racers measure 5.56m and 2.08m in diameter respectively along their midlines. Within the inner racer, granite paving surrounds the central iron pivot post, 0.38m high and 0.19m diameter, from which the pivot pin rises a further 0.12m. The magazine was cut into the rock along the 5m of inner face of the 16th century curtain wall beside the gateway. It has a flat roof and extends 3.75m from the curtain wall, faced to the north east by an uncoursed rubble wall, 4m high, alongside the gateway. The original route along the curtain wall to the blockhouse at the upper level was replaced by steps cut into the rock forming the south east side of the magazine. This phase of refurbishment was commemorated by a series of square granite plaques marked `WD 1855' affixed to the outer face of the curtain walls and bastion, and to the inner face of the south west length of curtain wall. Documentary sources record that in 1887, the Crimean War battery was armed by two 64-pounder rifled muzzle-loading (RML) guns, manned by Artillery Volunteers, and retained as a practice battery. This type of gun was obsolete by the end of the 19th century and the battery was abandoned. During World War II, from June 1940, St Catherine's Point became a gun battery and observation post, the various structures of which extended from this monument to the higher ground to the west. Within this monument, the south western of the two Crimean War gun emplacements became the site for one of the two guns which were this battery's initial armament. The 19th century RML gun mounting was removed and the emplacement was filled with concrete to the top of the 1855 rampart to serve as a solid foundation for mounting the gun, a 4.7-inch naval gun. A large concrete protective shelter was built around the gun and a concrete pill box, with a lower roof, was built alongside it. The Crimean War magazine beside the gateway was reused for its original purpose, as an ammunition store, while the 16th century blockhouse was used as the firing point for a controlled minefield laid across the mouth of the Fowey estuary. Other structures in the World War II battery were situated on higher ground from 50m west of this monument, where another 4.7-inch naval gun was mounted. After the war, the guns were dismantled in October 1945; in succeeding years the concrete shelter and gun foundation in and around the 19th century gun emplacement, together with the pillbox, were broken up and removed but the rock-cut recesses that accommodated them remain along the north west and south west faces of the lower platform. These faces bear slots, grooves and plug holes where the roofs, joists and walling of those structures were keyed in to the adjacent bedrock. All English Heritage notices, fixtures and fittings, power supply cables, drains and the harbour light are excluded from the scheduling but the ground beneath them is included.

MAP EXTRACT The site of the monument is shown on the attached map extract.


The contents of this record have been generated from a legacy data system.

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Books and journals
Keast, J, The Story of Fowey, (1987)
Keast, J, The Story of Fowey, (1987)
Keast, J, The Story of Fowey, (1987)
Keast, J, The Story of Fowey, (1987)
Keast, J, The Story of Fowey, (1987)
Morley, B, The Castles of Pendennis and St Mawes, (1988)
Morley, B, The Castles of Pendennis and St Mawes, (1988)
Richards, P, Reynolds, D, Fowey at War, (1993)
Richards, P, Reynolds, D, Fowey at War, (1993)
Rowse, A L, Tudor Cornwall, (1947)
Rowse, A L, Tudor Cornwall, (1947)
Stevenson, I V, Some West Country Defences, (1989), 11-26
Stevenson, I V, Some West Country Defences, (1989)
Stevenson, I V, Some West Country Defences, (1989)
Woodward, F W, 'Devon Archaeology' in Drake's Island, , Vol. 5, (1991)
consulted 1994, CAU, Cornwall SMR entry, PRN 26744, & CCRA Register entry SX 15 SW 11,
consulted 1994, DoE/HBMC, Ancient Monuments Terrier for CO 276, Fowey Castle, (1984)
consulted 1994, DoE/HBMC, Ancient Monuments Terrier for CO 276, Fowey Castle, (1984)
Shown to MPPA in Nov 1994, Shown by Mr & Mrs Read, Readymoney, Fowey, Engraving dated 1786 showing St Catherine's Castle, (1786)
Site discussed with MPPA, 23/11/1994, Information, plans & sketches from Mr Paul Richards, Fowey, (1994)
Title: 1:10000 Ordnance Survey Map: SX 15 SW Source Date: 1976 Author: Publisher: Surveyor:
Title: 1:10000 Ordnance Survey Map: SX 15 SW Source Date: 1976 Author: Publisher: Surveyor:


This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

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