St Mawes Castle, Gatehouse, Blockhouse, Magazine and Outer Defences

ST MAWES CASTLE, GATEHOUSE, BLOCKHOUSE, MAGAZINE AND OUTER DEFENCES

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Overview

Heritage Category:
Listed Building
Grade:
I
List Entry Number:
1136705
Date first listed:
25-Jun-1985
List Entry Name:
St Mawes Castle, Gatehouse, Blockhouse, Magazine and Outer Defences
Statutory Address:
ST MAWES CASTLE, GATEHOUSE, BLOCKHOUSE, MAGAZINE AND OUTER DEFENCES
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Date:
2004-04-06
Reference:
IOE01/12175/12
Rights:
© Mr Michael McCloy. Source: Historic England Archive

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Official list entry

Heritage Category:
Listed Building
Grade:
I
List Entry Number:
1136705
Date first listed:
25-Jun-1985
List Entry Name:
St Mawes Castle, Gatehouse, Blockhouse, Magazine and Outer Defences
Statutory Address 1:
ST MAWES CASTLE, GATEHOUSE, BLOCKHOUSE, MAGAZINE AND OUTER DEFENCES

The scope of legal protection for listed buildings

This List entry helps identify the building designated at this address for its special architectural or historic interest.

Unless the List entry states otherwise, it includes both the structure itself and any object or structure fixed to it (whether inside or outside) as well as any object or structure within the curtilage of the building.

For these purposes, to be included within the curtilage of the building, the object or structure must have formed part of the land since before 1st July 1948.

Understanding list entries

Corrections and minor amendments

The scope of legal protection for listed buildings

This List entry helps identify the building designated at this address for its special architectural or historic interest.

Unless the List entry states otherwise, it includes both the structure itself and any object or structure fixed to it (whether inside or outside) as well as any object or structure within the curtilage of the building.

For these purposes, to be included within the curtilage of the building, the object or structure must have formed part of the land since before 1st July 1948.

Understanding list entries

Corrections and minor amendments

Location

Statutory Address:
ST MAWES CASTLE, GATEHOUSE, BLOCKHOUSE, MAGAZINE AND OUTER DEFENCES

The building or site itself may lie within the boundary of more than one authority.

District:
Cornwall (Unitary Authority)
Parish:
St. Just-in-Roseland
National Grid Reference:
SW 84104 32752

Details

SW 84 32 ST JUST IN ROSELAND ST MAWES

7/118 St Mawes Castle, gatehouse, - blockhouse, magazine and outer defences GV I

Castle for coastal defence and including gatehouse blockhouse, magazine and outer defences. Built 1540-1543 for Henry VIII blockhouse early C16 also for Henry VIII, magazine is Victorian. Slatestone rubble walls with granite strings, copings, door and window frames and granite ashlar circular stair turret lookout rising above embrasure position with C17 lead ogee shaped roof with finial. Otherwise flat lead roofs over keep and bastions. Clover leaf plan of round keep with 3 adjoining semi circular bastions. Very thick walls to resist cannon fire. 3 storeys over kitchen basement. Entrance is through polygonal, slate roofed single storey gatehouse leading to 2 span bridge with parapets and originally with drawbridge. Oak door with wicket and original hinges. Doorway and other arches and openings elsewhere is four centred; flanking cross slits and chain slits over. Gunport with hoodmould overlooks gatehouse with coat of arms over. The surrounding seascape is overlooked by further similar gunports to all sides of 2nd floor of keep and to bastions. Battlemented parapets to keep and bastions with provision for mantlets. Southern entrance has Royal coat of arms over flanking by Tritons bearings inscribed scroll, inscriptions. Further inscription on string under keep battlements which is punctuated by gargoyles. Keep has 2, 4 and 6 light mullioned windows, some with king mullions, to basement, ground and first floors all protected by bastions. Interior of keep has original granite newel stair leading to all floors plus further stairs to bastion parapets. Circular, 1 room kitchen in basement has large fireplace with large oven, some original floor beams (originally ceiled) on granite posts and niche by stair over moulded pedestal. Octagonal, 1 room ground floor, originally the mess room with 2 small rooms within wall thickness, 1 with fireplace and keeping place, further recess, probably garderobe. Main fireplace has overmantle with pediment. Octagonal 1st and entrance floor has half partitioned off creating 2 rooms flanking passage, probably chambers, and main room ie hall in remainder. Fireplace to each room; the main one with niche over, oven left and linked keeping place right. Some original carved oak door heads survive. To right of main entrance is deep shaft with small room at the bottom. Second floor ie. the gunroom is octagonal with deep gunport to each side. Beside the gunports here and in bastions are niches possibly for powder or shot. Overhead smoke vents now blocked. Well is cut in moat wall near bridge and stone slab in basement possibly covers further well. Blockhouse built before main castle, now roofless, has 3 gun ports, large oven and water cistern. Magazine mid to late C19 to south has low pitched masonry roof with granite coping and cornice and doorcase of granite with low pitched gable echoing main roof. Of similar date are further gun emplacements. Mostly uneventful history, being surrendered in March 1646 by Hannibal Bonython, lieutenant of the castle to Fairfax, the parliamentary General after a brief discussion of terms without a shot being fired. St Mawes Castle is described in greater detail in the castle guide which is based on Illustrated Guide to St. Mawes and Pendennis castles by Miss Daphne Drake. Some information from Ministry of Works guide, Henry VIII and the Development of coastal Defence (H M S O) and Castles of Cornwall by Mary and Hal Price. Scheduled Ancient Monument 278.

Listing NGR: SW8410432752

Legacy

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

Legacy System number:
63079
Legacy System:
LBS

Sources

Books and journals
Drake, D, Illustrated Guide to St Mawes and Pendennis Castles, ()
Price, M, Price, H, Castles of Cornwall, (1980)
Ministry of Works Guide in Henry VIII And The Development Of Coastal Defence, ()

Legal

This building is listed under the Planning (Listed Buildings and Conservation Areas) Act 1990 as amended for its special architectural or historic interest.

Ordnance survey map of St Mawes Castle, Gatehouse, Blockhouse, Magazine and Outer Defences

Map

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© Crown copyright [and database rights] 2026. OS AC0000815036. Use of this mapping is subject to Terms and Conditions.

End of official list entry

All text content is available under the Open Government Licence v3.0 , except where otherwise stated. Any supplied maps are © Crown Copyright [and database rights] 2026 OS AC0000815036 and may not be reproduced without permission.

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