Castle Down bastion
Has been described as a Possible Artillery Fort
There are earthwork remains
| Name | Castle Down bastion |
| Alternative Names | |
| Historic Country | Isles of Scilly |
| Modern Authority | Isles of Scilly |
| 1974 Authority | Isles of Scilly |
| Civil Parish | Tresco |
Outwork from C16 surviving as a bank 2.5m wide and 0.2m high with an occasional outer or south facing ditch. It is a setting out work with a south facing bastion with orillons in the centre of Castle Down plateau. West from the main bastion are traces of another which appears to be unfinished. (PastScape)
On the ground it appears, for the most part, as a bank 2.5 m wide and 0.2 m high with, occasionally, an outer or southward facing ditch 1.5 m wide and 0.1 m deep. It is clearly a setting out work with a massive south facing bastion with orillons set in the centre of Castle Down plateau. From it two 75.0 m lengths of walling would form an angle of 120. At the east end of the 'wall' there is a half bastion from which a scarp extends northwards for 60.0 m along the crest of the steep coastal slopes and ending at some out- cropping rock. Going westwards from the main bastion for 75.0 m there are traces of another which seems to have been unfinished in its setting out. Its plan, however, would, of necessity have been distorted since it is on the lip of the coastal slopes at this side of the island. There is a gap of 30.0 m and then a flanking scarp, similar to that on the east but slightly below the crest of the plateau, can be traced for 60.0 m towards the 16th century, mis-named, King Charles' Castle. The flanking scarp ceases near a small quarry pit. This unfinished and previously unrecorded fortification would have enclosed some 36 hectares of the north part of Tresco. Commenting on the earthwork Mr A D Saunders says the work "is clearly 16th century in form. The shape of the bastions suggests it could belong to the 1550's, contemporary with Harry's Walls, and designed as an outwork to King Charles Castle". (PastScape)
This site is a scheduled monument protected by law
Not Listed
Historic England (PastScape) Defra or Monument number(s)
County Historic Environment Record
| OS Map Grid Reference | SV885160 |
| Latitude | 49.9627914428711 |
| Longitude | -6.34470987319946 |
| Eastings | 88570 |
| Northings | 16050 |
