Post-medieval smugglers' cache at Porth Mellon, 110m west of Harry's Walls Battery, St Mary's


Heritage Category: Scheduled Monument

List Entry Number: 1015668

Date first listed: 21-Jan-1999


Ordnance survey map of Post-medieval smugglers' cache at Porth Mellon, 110m west of Harry's Walls Battery, St Mary's
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The building or site itself may lie within the boundary of more than one authority.

District: Isles of Scilly (Unitary Authority)

Parish: St. Mary's

National Grid Reference: SV 90866 10920


Legacy Record - This information may be included in the List Entry Details.

Reasons for Designation

The Isles of Scilly, the westernmost of the granite masses of south west England, contain a remarkable abundance and variety of archaeological remains from over 4000 years of human activity. The remote physical setting of the islands, over 40km beyond the mainland in the approaches to the English Channel, has lent a distinctive character to those remains, producing many unusual features important for our broader understanding of the social development of early communities. Throughout the human occupation there has been a gradual submergence of the islands' land area, providing a stimulus to change in the environment and its exploitation. This process has produced evidence for responses to such change against an independent time-scale, promoting integrated studies of archaeological, environmental and linguistic aspects of the islands' settlement. The islands' archaeological remains demonstrate clearly the gradually expanding size and range of contacts of their communities. By the post- medieval period (from AD 1540), the islands occupied a nationally strategic location, resulting in an important concentration of defensive works reflecting the development of fortification methods and technology from the mid 16th to the 20th centuries. An important and unusual range of post- medieval monuments also reflects the islands' position as a formidable hazard for the nation's shipping in the western approaches. The exceptional preservation of the archaeological remains on the islands has long been recognised, producing an unusually full and detailed body of documentation, including several recent surveys.

Smugglers' caches are hidden stores where contraband goods were concealed from the authorities, potential informants and rivals. Rising trade, demand and taxation affecting imported commodities such as tobacco, spirits, and tea during the 17th and 18th centuries, coupled with few effective controls on maritime activity outside the major ports, encouraged an illicit trade by smugglers profitting by avoiding payment of duty on goods run across from the Continent or acquired at sea from trading vessels in the Channel. Trade in contraband goods was especially rife along most of the south coast of England, facing the Continent; some small ports and coastal villages in Kent, Sussex and the south west achieved notoriety for their smuggling activity, involving large numbers of vessels and men and forming a significant part of the economy in some areas by the mid-18th century. Early counter-measures included a network of Customs Stations whose collectors controlled Revenue Cutters, sometimes supplemented by naval vessels. Despite some limited success, their resources were too thinly stretched and could not match the local knowledge of the coastline of the smugglers. Increasingly effective control only came with the ending of the wars with France when, in 1816-17, the Customs was considerably expanded to include the new Coastguard, with sufficient manpower to operate as a widespread preventative force along the south coast. In conjunction with stringent penalties, including the destruction of vessels caught engaged in smuggling, the trade in contraband goods had been severely reduced by the 1840s. Accounts of successful anti-smuggling actions by Customs and the Coastguard forces reveal a variety of ingenious methods adopted in the early 19th century to conceal smuggled goods after their arrival and before or during their distribution, reflecting the increased pressure on the smugglers activities. In addition to securing the contraband beneath the surface of the sea, fixed to weights on the sea-bed, other favoured sites of temporary storage included hidden caches constructed within, beneath or near dwellings or public houses used by the smugglers. Until the establishment of the Coastguard, conditions in the south west of England proved especially favourable for smuggling, with its deeply indented coastline remote from the centres of authority and administration but conveniently facing the Continent and adjacent to the trade routes entering the Channel. The enhancement of these factors in regard to the Isles of Scilly was used to advantage by many among its population, as is testified by the repeated complaints of successive Customs collectors based there. The importance of smuggling as a vital supplement to the islands' economy of the 18th and early 19th century is shown by a petition in 1819 to relieve the islanders' poverty, citing the effectiveness of the new preventative force as a main cause of their distress. Apart from historical references and association with some surviving buildings on Scilly, this formerly important activity leaves relatively few remains, chief among which are smugglers' caches and a series of 19th century lookout points set up and used by the Coastguard force. Three smugglers' caches are known to survive on Scilly, one on St Mary's and two on Tresco. Each is visible as an underground passage in a hidden location separated from nearby dwellings and each is of differing form. The number of such smugglers' caches that survive nationally is not known and by their intentionally-concealed nature, more are likely to survive than have been recorded. Smugglers' caches provide one of the few surviving remains of an activity which demonstrates the interplay of developing trade and law enforcement efficiency during the post-medieval period. The smugglers' cache at Porth Mellon survives well, retaining clear evidence for its manner of construction, and it is the largest example of such a cache on Scilly. Its concealed siting is typical but it is the only known surviving example located in such close proximity to the main anchorage and centre of population on the islands. Its 19th century date, evidenced by the stone-splitting method employed, reflects the increasing pressures from the authorities at that time which resulted in the need for such caches.


Legacy Record - This information may be included in the List Entry Details.


The monument includes a small stone-lined smugglers' cache, a hidden store for contraband goods, dating to the 19th century and situated behind the north east cliff of Porth Mellon on the west coast of St Mary's in the Isles of Scilly. The smugglers' cache is visible as a short underground passage, 5m long, up to 0.9m wide and 1m high, cut NNW-SSE behind the upper cliff of Porth Mellon. From a flat silt-covered floor, the sides of the passage rise vertically, faced by six courses of slabs and cobbles, some roughly shaped but not dressed flat. It is roofed by long slabs laid across the passage, resting at each end on the coursed facing. Some facing and roof slabs bear drilled holes along split edges, showing a stone-splitting method that appeared in general use c.AD 1800. The passage curves slightly southward as it progresses to its SSE end, to which the floor also descends gradually. At the SSE end itself, the stonework of the passage sides and roof ends abruptly at a layer of soil and rubble through which a roughly dug access pit rises steeply to the surface. Fragments of 19th century pottery occur in the soil partly collapsing into this pit. The NNW end of the passage opens directly onto a turf-covered ledge in the upper cliff; the south west wall facing extends 0.7m beyond the NNW lintel indicating some robbing of larger stones from the original NNW end of the passage. The exposed section across the passage at this end reveals how it was built. The passage was originally dug as a trench, 1.8m wide and 1.8m-2m deep, cutting deeply into the orange subsoil. The coursed facing walls, 0.5m thick, were then built along the sides of the trench and the roofing slabs were laid across. The resulting structure was then covered by redeposited subsoil, soil and rubble, infilling the trench and merging it with the surface profile of the surrounding coastal margin. This smugglers' cache is located beside the broad bay of Porth Mellon, facing the islands' main sheltered anchorage of St Mary's Pool and close to the focus of the islands' population and trade at Hughtown, 0.3km to the south west. It is also at a point on the coastal margin hidden from view from many angles, and from most of Hughtown by the small coastal promontory of Carn Thomas and the ridge extending south east from it.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 2 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.


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

Legacy System number: 15483

Legacy System: RSM


Books and journals
Ashbee, P, The chambered Tombs on St Mary's, Isles of Scilly, (1963), 9-18
Ashbee, P, Ancient Scilly, (1974)
Gerrard, S., English Heritage Book of Dartmoor, 1997, Forthcoming
Parkes, C, AM 107 for Scilly SMR entry PRN 7569, (1988)
Title: 1:2500 Ordnance Survey Map; SV 9010 Source Date: 1980 Author: Publisher: Surveyor:

End of official listing