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Archaeology Notes

Event ID 676315

Category Descriptive Accounts

Type Archaeology Notes


NN30NW 2 32271 09569

(NN 3226 0954) Castle (NR) (Remains of)

OS 6" map, Dunbartonshire, 2nd ed., (1923)

The earliest and principal stronghold of the Clan Macfarlane was at Inveruglas. When this castle was destroyed by Cromwell's troops in the time of Charles I, the chief of the Macfarlanes took up residence at Tarbet and Ellan Vhow (Built 1577 - NN31SW 2). The remains of the castle are in the form of a parallelogram flanked by towers 40' high.

D Macleod 1891; W Fraser 1869; J Irving 1879.

The remains of a Z-plan castle with rounded towers on the NE and SW angles measuring overall 12.0m x 9.5m. The walls stand to a height of 3.5m and are 1.3m thick. Adjacent are the remains of two rectangular buildings (the largest measuring 13.0m x 5.0m with walls 0.5m high in places) which appear to post-date the castle.

Surveyed at 1:10,000.

Visited by OS (J L D) 28 September 1956 and (I A) 23 March 1973.

NN 322 095 The remains of a Z-plan castle stand on Inveruglas Isle in Loch Lomond. The castle was abandoned in the mid-17th century.


W Fraser 1869; J Irving 1879

The island is dominated by the remains of the castle which is a rectangular tower with different sized round towers at the NE and SW corners. Once the stronghold of the MacFarlanes it was destroyed by soldiers loyal to Cromwell during the Commonwealth of 1649 to 1660 (perhaps c.1654). A sword and set of keys were found in the ruins some years ago.

The towers are later additions to the main tower block and appear to represent a later strengthening of the defences. The standing walls are built entirely of sandstone and are very obviously burnt. The castle stands no higher than the first floor and it is apparent that its destruction in the mid 17th century was comprehensive.

Two rectangular drystone buildings lie on the E side of the castle. It is impossible to ascertain whether these are associated with the castle or later structures. Both are overgrown and the S building is almost imperceptible except for its N wall.

There is a fine drystone jetty and landing stage (NN30NW 20) at the SE corner of the island. This jetty, now overgrown and inaccessible, is a substantial construction and it is suggested it is the landing stage associated with the use of the castle.

The castle incorporates the bedrock outcropping into its construction and this can be clearly seen on the N, W and S sides.

The castle is well provided with firing slots, of those that survive all are square or rectangular.

The interior of the castle is filled with rubble and vegetation and nothing can be determined about the ground floor level and it is unknown if there was a vaulted basement or ground floor although no evidence of one was observed.

At first floor level the main tower wall is 'benched' or of double thickness. This suggests an internal passageway was present along the wall all around the first floor. This may represent a kind of internal parapet or that intra to mural passages and probably also a stair were a feature of the castle.

At first floor level fireplaces are present in both the N and S walls and one would expect the first floor to be taken up by the hall.

Two firing slots are present below first floor level in both the N and E walls. These firing slots are quite different from the firing slots seen in the towers and have splayed ingos. Their level within the wall is a little puzzling as the level of the ground floor is unknown but they may be indicative of the earlier defensive arrangements of the castle.

The towers at the NE and SW corners are of different sizes with the SW tower being considerably larger. Both towers appear to have been entered from the first floor from the interior of the castle and it is probable the SW tower also had an external entrance. The interior of both towers changes from being circular in plan to square in plan at first floor level. The exterior of the towers is circular to their full height. Both towers are provided with at least 5 firing slots at 2 levels, (first and second floors), ensuring all round coverage and the circular face would also have helped to deflect missiles.

The walls of the castle survive to different heights varying between 1.70m to 6.20m.

The Castle is constructed of sandstone boulders which had been quarried elsewhere and brought to the island. The stones are rough and undressed. Occasional quartz boulders also in the construction. Well built straight walls with smaller stones pegging the masonry between the main courses of boulders. The courses are obvious and fairly regular. Bedrock outcrops have been incorporated into the castle's construction on all sides and it is possible it was quarried to form a level foundation surface in places and particularly on the E side. It is impossible to determine the internal arrangements of the castle below first floor level due to tumbled masonry including some large mortared chunks of wall and vegetation filling the interior.

The walls are mortar bonded and harling is present in a few places.

The castle is, naturally, defensive in nature and all the firing slots are designed for muskets rather than arrows. The quoins are very integral to the construction and are not obvious or specially dressed blocks but rather stones of a suitable size. The quoins at the NW corner are much more distinct than those at the SE corner.

The firing slots described as being at ground floor level are actually quite high up in the wall and not far below the first floor level. Those in the S and W walls could not be seen from the interior. The ground floor firing slots in the N and E walls are at slightly different levels suggesting the bedrock outcropping may have the main determining factor in their location.

There is no apparent building break at first floor level to account for the benched wall and it appears the thinning of the wall is an original feature of the castle's construction.


Harling is present on all external faces which also show extensive evidence of burning.

E Wall: one firing slot angled downwards to a 0.3m by 0.3m aperture, located towards N end of wall but fairly central and at ground floor level. Visible from both interior and exterior. The foundation appears to be constructed directly onto a bedrock ledge which may be quarried and which projects from the base of the wall. The modern entrance at the S end of the wall does not appear to be original though it does appear as if a jamb of some kind may have been removed. The E wall stands to a maximum height of c.1.70m.

S Wall: one downward angled firing slot opening to an aperture 0.3m by 0.35m. Now filled with rubble suggesting it is either filled with collapsed masonry or that it was deliberately blocked during the castle?s use. Only visible from the outside. The S wall remains standing to a height of c.2.40m. There is tumble along the S wall, particularly in the vicinity of the tower.

W Wall: two downward angled firing slots located at ground floor level though high up in the wall and just below first floor level. They could not be seen from the interior. There is robbed masonry from the centre of the wall which may represent the blocking of an earlier feature that was later robbed or possibly even damage from explosives that may have been used by the Cromwellian troops. The wall rises over and is built onto a bedrock outcrop at its N end. The W wall stands to a maximum height of c.4.60m.

N Wall: the wall rises up over bedrock at the E end and is built onto it. One firing slot with a downward angle towards the E end providing additional defence of this weaker point where the bedrock outcrop would have been of use to attackers. This firing slot is visible in the interior. From the exterior it appears very low set and it is possible this may have been a rubbish shoot rather than a firing slot though it appears to be a firing slot from the interior. The N wall stands to the greatest surviving height of all the walls at c.6.20m.

NE Tower: There are five firing slots at first floor, (lower), level and 3 firing slots survive at second floor level on the N and W sides. The S and E sides of the tower have collapsed at this level and it is probable firing slots were present around the whole circuit. All the firing slots have square or rectangular apertures and are on average 0.3m by 0.25m at the external opening. Burning can be clearly seen at the openings and may be due to powder burns from musketry or from the burning down of the castle. It is clearly apparent that the tower is later than then the body of the castle and the abutment of the tower to both the N and E walls is very noticeable.

SW Tower: six firing slots are present at ground floor level, all are angled downwards on the E side and they tend to be square at c.0.3m by 0.3m as opposed to the ones on the W which are rectangular and c.0.23m by 0.35m. This tower is larger than the tower at the NE angle and is also clearly later than the rectangular body of the castle with once again very clear wall relationships. This tower is built on a bedrock outcrop along its S and E sides and the firing slots are to be found at c.1.60m above ground surface on the N and W sides and only c.0.5m above ground level on the S and E sides. At first floor level there is a large aperture either a window or a door. Considering the generally defensive nature of the castle it seems more likely to be a door. Only the E jamb remains entire in situ and a fragment of the W jamb. The sill and lintel have been robbed. 1 firing slot and the fragmentary remains of one other remain at first floor level.


E Wall: this wall is very overgrown and tumbled making it impossible to determine if the benching was present on this wall. The firing slot is very similar to the one in the N wall although set at a slightly higher level in the ground floor.

S Wall: nothing could be determined about the S wall below first floor level. At first floor level the wall is benched with an internal wall thickness of 0.4m and an outer wall thickness of 0.7m making an overall thickness of 1.10m. A fireplace is located towards the centre of the S wall and the wall is only 0.3m thick at this point. The fireplace has stepped jambs and a lot of harling remains in situ.

W Wall: no defensive features are visible on the interior at all and nothing much could be determined about the wall below first floor level except that the wall is of an even thickness up to first floor level and this is true of all the walls. The inner wall is 0.9m thick and the outer wall 0.7m thick making an overall thickness of 1.60m, considerably thicker than the S wall.

N Wall: the N wall has a firing slot at ground floor level which is 1m tall and 0,90m wide at the interior tapering to a firing slot of c.0.3m by 0.35m. The firing slot is 1.30m deep. At first floor level the inner wall is 0.9m thick and the outer wall is 0.4m thick. A fireplace is present in the centre of the wall with possible traces of the chimney visible in the standing masonry.

NE Tower: the interior of the tower is circular up to first floor level where it becomes square. The entrance is now blocked with fallen masonry but is clearly visible entering the main castle block at the easternmost end of the N wall. The firing slots are not uniform in their dimensions and they are angled as appropriate to give the best defensive cover.

SW Tower: the interior of the tower is circular up to first floor level where it becomes square. A scarcement is present in the SE part of the tower at first floor level suggesting a floor was present although this ledge may be associated with the large window or doorway in the S face. The large opening at first floor level tapers towards the exterior. Although this opening is rather narrow it seems more likely to have been a door than a window. The sills of all the firing slots have been robbed leaving the mortar and rubble core exposed. The firing slots are not of uniform dimensions though all taper towards the exterior. The firing slots are on average 0.9m wide by 0.6m tall on the interior and taper to apertures of 0.3m by 0.3m or 0.3m by 0.25m at the exterior. The mortar in the firing slots appears burnt and is discoloured to red, black and grey. This may be a result of their use with muskets or from the burning of the castle or even a combination of the two. The tower walls are c.0.9m thick.

To the E of the tower, there are two buildings. The E of these is a rectangular stone structure orientated N to S and measuring 13.10m by 5.60m over walls on average 0.8m thick. An entrance, c.1m wide, is located in the E wall. The walls remain standing to 0.8m maximum. The walls are quite denuded and it was not possible to determine if the corners were rounded or square. The walls consist of a rubble core containing slate, suggesting the structure may be later than the castle, and possibly also a turf core faced with drystone walling. No traces of mortar were seen nor of any internal partitions. The remains are overgrown by moss, lichen and woodrush. The structure appears to taper slightly towards the N end.

By the SW corner of the building, there is a rectangular drystone structure. Very overgrown and difficult to distinguish except for the N wall. The N wall is c.0.7m wide and stands to 0.4m maximum. The overall dimensions, including the walls, are approximately 8.70m N to S by 4.40m E to W. The relationship of this structure to the castle could not be determined.

FIRAT 1995; NMRS, MS/993/2.

Scheduled as Inveruglas Castle, Inveruglas Isle, Loch Lomond.

Information from Historic Scotland, scheduling document dated 8 December 2000.

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