Ancient Monuments

History on the Ground

This site is entirely user-supported. See how you can help.

Ennor Castle, Old Town, St Mary's

A Scheduled Monument in St. Mary's, Isles of Scilly

We don't have any photos of this monument yet. Why don't you be the first to send us one?

Upload Photo »

Approximate Location Map
Large Map »

If Google Street View is available, the image is from the best available vantage point looking, if possible, towards the location of the monument. Where it is not available, the satellite view is shown instead.


Latitude: 49.9135 / 49°54'48"N

Longitude: -6.3 / 6°17'59"W

OS Eastings: 91416.043361

OS Northings: 10348.917055

OS Grid: SV914103

Mapcode National: GBR BXTX.C3Z

Mapcode Global: VGYC4.RF9M

Entry Name: Ennor Castle, Old Town, St Mary's

Scheduled Date: 7 October 1976

Last Amended: 29 May 1996

Source: Historic England

Source ID: 1014994

English Heritage Legacy ID: 15469

County: Isles of Scilly

Civil Parish: St. Mary's

Traditional County: Cornwall

Lieutenancy Area (Ceremonial County): Cornwall

Church of England Parish: Isles of Scilly

Church of England Diocese: Truro


The monument includes a small shell keep castle known as Ennor, or Old Town,
Castle in the present village of Old Town on the south coast of St Mary's in
the Isles of Scilly.
The castle occupies a small but prominent knoll on the east side of the broad
Lower Moors valley behind Old Town Bay. The knoll has a semicircular rocky
scarp facing west, up to c.10m above the valley floor, from which the knoll
slopes steeply to more gently sloping land to the east. The castle encompassed
the knoll with a subrectangular keep wall, now partly dismantled. An outer
earthwork bank is visible along the foot of the slope and traces of walling
indicate an adjacent enclosure south east of the knoll.
The walls of the sub-rectangular keep no longer survive in their entirety
above ground level. The wall survives above ground on the north west and part
of the west side, where it is c.1m thick, of coursed rubble. Its footings vary
in height with irregularities in the knoll, and the wall's height thus also
varies, averaging 1m above interior ground level but reaching 2m high in
places. Elsewhere, the line of the wall is now marked by earthwork banks
between 2m and 4.5m wide and 1m to 1.5m high along the south west and east
sides, and by a wider spread of dense rubble on the south east side.
The keep's walls defined a subrectangular internal area measuring 22m north
east-south west by up to 17m north west-south east, rounded at the south west
end and squared at the north east. The interior of the castle has only a
limited level area behind the south west end, beyond which the surface slopes
fairly steeply. Internal buildings, typically of timber within small shell
keep castles, have left no visible remains above ground level.
An outer earthwork extends along the foot of the slope north east of the keep.
It survives as a slight bank up to 0.25m high.
Also beyond the keep, a short exposure of walling extends from the southern
end of the knoll's outcrops, implying an adjacent enclosure south east of the
keep. The wall is built of coursed rubble, 0.5m high and is visible over 2m
before becoming covered by later deposits. The wall runs along slightly
elevated land extending south east from the knoll; this area has been subject
to relatively recent gardening and the survival of earlier features is
Surviving historical sources add to our knowledge of Ennor Castle. The
earliest reference to Ennor Castle is in a deed of AD 1244, by which time
Ennor (or `La Val' in Anglo-Norman documents) had been the main settlement on
St Mary's for some time. By 1306 Ranulf de Blanchminster held the castle in
return for the provision of 12 men-at-arms to maintain the peace and the
payment of an annual tribute to the king of 6s 8d or 300 puffins at
Michaelmas, a tribute whose actual payment was always recorded in money. A
royal licence to crenellate (ie to defend) the castle was granted to Ranulf in
1315 but in 1337, the castle along with the rest of Scilly, was included in
the lands of the newly created Duchy of Cornwall. In c.1540, the King's
Antiquary, John Leland, described the castle as `a meately strong pile'. It
still formed an effective fortification, and in May 1554 a survey records that
Ennor Castle was armed with cannon.
The fortunes of the castle and its adjacent settlement were finally eclipsed
when the fortification of Scilly was revised to serve national defensive
considerations in the late 16th century, when the Star Castle was built. At
the same time the focus of settlement and trade also moved to St Mary's Pool,
leaving Ennor Castle redundant and Ennor's town and harbour in decline. A
survey of 1652, refers to the settlement at St Mary's Pool (the present
Hughtown) as `Hue or New Towne', while Ennor was termed `Old Town'.
By local tradition, the castle was dismantled to build the Star Castle, but
in view of the distance it is more likely that Ennor Castle was progressively
dismantled to provide building stone for more local purposes in Old Town.
The modern water storage and header tanks, their pipes and fittings and the
pipe-support blocks are excluded from the scheduling but the ground beneath
them is included.

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.

Source: Historic England

Reasons for Scheduling

A shell keep castle is a masonry enclosure extending around the top of raised
mound which is often, but not always, derived from an earlier fortification;
the enclosure is usually rounded but other shapes are known. A shell keep is
relatively small, normally between 15m and 25m across, and is seldom more than
one storey high. Unless supplemented by excavated evidence, few traces of
internal buildings are generally found as they were usually of wood, only
rarely being replaced in stone. Shell keeps were built over a period of about
150 years from the end of the 11th century to the mid 13th century; most were
built in the 12th century and provided strongly fortified residences for the
king or leading families. Shell keep castles are widely dispersed throughout
England, with a marked concentration in the Welsh Marches and with a
distribution extending into Wales and to a lesser extent into Scotland. They
are a rare class of monument, with 71 recorded examples nationally, of which
only one is situated in the Isles of Scilly. They display a considerable
diversity of form, with no two examples exactly alike. Along with other
contemporary forms of castle, they are major medieval monuments which,
belonging to the highest levels of society, frequently acted as administrative
centres and formed the foci for developing settlements. Consequently they form
valuable sources of information on medieval society, its settlement and
trading patterns, and on medieval defensive methods.

Ennor Castle survives in recognisable form despite dismantling of much of the
keep wall. Sufficient evidence survives to determine the overall ground plan
while the interior has not been archaeologically excavated or redeveloped and
will retain buried evidence for its internal features. With the broadly
contemporary church and quay at Old Town, it forms one of the three major and
surviving elements of the main secular settlement on Scilly during the
medieval period. Its location relative to the settlement and its historically
recorded tenure demonstrate the role and setting of shell keep castles.
The sequence of occupation and decline of Ennor Castle also illustrates the
interdependence of such castles with their wider settlement context. Its
decline shows particularly clearly the impact of change at national level
in the 16th century. Ennor Castle is the only medieval castle on the Isles of
Scilly. It is also the earliest element in an almost continuous sequence of
fortifications on the islands, which extends to the end of World War II and
which is itself nationally very rare in terms of completeness and quality of

Source: Historic England


Books and journals
Bowley, R L, The Fortunate Islands: A History of the Isles of Scilly, (1968)
Ratcliffe, J, The Archaeology of Scilly, (1989)
Ratcliffe, J, Scilly's Archaeological Heritage, (1992)
Thomas, C, Exploration of a Drowned Landscape, (1985)
Saunders, A D, 'Cornish Archaeology' in Harry's Walls, St Mary's Scilly; a new interpretation, , Vol. 1, (1962), 85-91
In conversation on 23/11/1993, Tradition told to MPPA by castle's owner, Mr Gren Hardern, (1993)
Keystone Historic Buildings Consultants, Star Castle, St Mary's, Isles of Scilly, 1993, Unpublished report for EH
Rees, S E, AM 7 scheduling documentation for SI 990, Remains of Old Town Castle, 1975,
Release 00, January 1989, Leach, PE, Monument Class Description 'Shell Keeps', (1989)
Title: 1:2500 Ordnance Survey Map; SV 9110
Source Date: 1980

Waters, A/CAU, AM 107 for Scilly SMR entry PRN 7544, (1988)

Source: Historic England

Other nearby scheduled monuments is an independent online resource and is not associated with any government department. All government data published here is used under licence. Please do not contact for any queries related to any individual ancient or schedued monument, planning permission related to scheduled monuments or the scheduling process itself. is a Good Stuff website.