Agaton fort


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.

City of Plymouth (Unitary Authority)
National Grid Reference:
SX 45569 59526


Royal Commission fortification known as Agaton Fort.

Reasons for Designation

The Royal Commission fortifications are a group of related sites established in response to the 1859 Royal Commission report on the defence of the United Kingdom. This had been set up following an invasion scare caused by the strengthening of the French Navy. These fortifications represented the largest maritime defence programme since the initiative of Henry VIII in 1539-40. The programme built upon the defensive works already begun at Plymouth and elsewhere and recommended the improvement of existing fortifications as well as the construction of new ones. There were eventually some 70 forts and batteries in England which were due wholly or in part to the Royal Commission. These constitute a well defined group with common design characteristics, armament and defensive provisions. Whether reused or not during the 20th century, they are the most visible core of Britain's coastal defence systems and are known colloquially as `Palmerston's follies'. All examples are considered of national importance. Despite adaptive re-use, the widening of the original gateway and the demolition of some structures the Royal Commission fortification known as Agaton Fort survives comparatively well and enough remains to understand the function, use and strategic military objectives of the structure and its armaments. It forms part of a much larger defensive network around Plymouth and represents the strategic, military response to a perceived historical and political threat. As such it is one of a rare number of such defensive works, which continued in use by the military until after the Second World War.


See Details.


This record was the subject of a minor enhancement on 14 October 2015. This record has been generated from an "old county number" (OCN) scheduling record. These are monuments that were not reviewed under the Monuments Protection Programme and are some of our oldest designation records.

The monument includes a Royal Commission fortification known as Agaton Fort situated on a raised knoll overlooking the River Tamar and situated on the north western side of Plymouth. Agaton fort survives as an irregular five-sided pentagonal work surrounded by a ditch on all sides except for the gorge, which is protected by musketry loops in its parapet and casements. The gorge was also protected by the east caponier. The other flanks have one single and one double caponier and a counterscarp gallery all bomb proof and designed to contain guns and musketry. Internally, the entrance is flanked by an officer’s quarters, cookhouse and store to the west and a bomb proof casemented barrack to the east. The main magazine is located under the south east corner of the rampart. The rampart has seven 1880s open gun positions and one 1860s Haxo casement on the western side separated by five expense magazines. Two 1860s mortar batteries remain intact at the east and north west salients with access via tunnels (now blocked) from the parade ground. Construction of the fort began in 1863 and was completed in 1869. Originally there were 20 gun emplacements all in open battery, except for one in a Haxo casement. Four more Haxo casements were built and a total of six mortars. The original guns were disarmed in 1893. There are Second World War foxholes at the east, north east and north west salients and the interior held Nissen huts and buildings for some time, the fort ceased military use in 1958.


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

Legacy System number:
PY 841
Legacy System:


PastScape Monument No:-437452


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.

End of official listing

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