Listed Building

The only legal part of the listing under the Planning (Listing Buildings and Conservation Areas) (Scotland) Act 1997 is the address/name of site. Addresses and building names may have changed since the date of listing – see 'About Listed Buildings' below for more information. The further details below the 'Address/Name of Site' are provided for information purposes only.

Address/Name of Site


Status: Designated


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Group Category Details
Date Added
Local Authority
Orkney Islands
Planning Authority
Orkney Islands
Birsay And Harray
HY 26434 22458
326434, 1022458


1941-43. Pair of partially dug-in, hexagonal, WWII pillboxes with grass roof coverings located at S and E perimeters of former Royal Naval Air Service (RNAS) set in open landscape comprising Twatt Airfield (former HMS Tern). Brick and shuttered concrete construction with overhanging flat roof; small square loophole to each elevation.

Statement of Special Interest

Part of a B Group at Twatt Airfield including: Combined Control Tower and Operations Block; 5 Air-Raid Shelters; 2 Pillboxes (see separate listings).

This pair of concrete WWII pill-boxes at the former Twatt Airfield are a good contextual survival within their building type. Situated at the southern and eastern perimeters of the airfield, the roofs of the hexagonal pillboxes are grass-covered as a camouflage measure. Corrugated sheeting has been used to shutter the concrete giving the pillboxes a distinctive appearance. The pillboxes are positioned to provide interlocking fields of fire over the anticipated southerly direction of attack. The loopholes are angled to limit access of incoming fire.

Twatt Airfield was an important Second World War Naval airfield in Orkney. Begun in 1940 and commissioned as HMS Tern in 1941 as a satellite of Hatston airfield for the Royal Marine engineers, it remained in service until 1949. The interest of the shelters is increased by the survival of various other associated WWII structures at Twatt, largely in shell form. The combined control tower and operations block (see separate listing) is the principal building of note. Of the four main military airfields in Orkney, Twatt has the most complete level of surviving WWII infrastructure with little now remaining at Hatston, Skeabrae or Grimstter (Kirkwall). The surviving elements include 5 air-raid shelters (see separate listing), the brick shells of the vehicle and parachute stores, ammunition stores, sick bay/decontamination unit and generator house and the projection room section of the former cinema. None of the aircraft hangars remain.

Air defences in Orkney were a significant contributor to national security with strikes from airfields in Orkney countering U-boat, surface vessel and air threats over the North Sea and at Scapa Flow. The hub of the Royal Navy's sea base operations were located at Lyness at the entrance to Scapa Flow including the Wee Fea Naval Communications and Operational Centre (see separate listing).

The airfield covered 440 acres of land in 1941 and was extended to a total of 564 acres in 1943. There are three adandoned 19th century farmsteads within the perimeter. Royal Navy Air Stations were separate from the Air Ministry and therefore developed their own distinct airfield architecture and layout, tending to have 4 intersecting runways rather than the 'A' plan layout favoured by the Air Ministry (RAF).



Civil Engineer in Chief's Dept, Plan of R.N.A.S - Twatt S2559/44 (1944). D J Smith, Action Stations 7: Military Airfields Of Scotland, The North East And Northern Ireland (1983). G Lamb, Sky over Scapa 1939-1945 (1991) pp23. Ed B Lowry, 20th Century Defences In Britain (1996) p79. RCAHMS, - accessed 2011. Further information courtesy of Birsay Heritage Trust.

About Listed Buildings

Historic Environment Scotland is responsible for designating sites and places at the national level. These designations are Scheduled monuments, Listed buildings, Inventory of gardens and designed landscapes and Inventory of historic battlefields.

We make recommendations to the Scottish Government about historic marine protected areas, and the Scottish Ministers decide whether to designate.

Listing is the process that identifies, designates and provides statutory protection for buildings of special architectural or historic interest as set out in the Planning (Listed Buildings and Conservation Areas) (Scotland) Act 1997.

We list buildings which are found to be of special architectural or historic interest using the selection guidance published in Designation Policy and Selection Guidance (2019)

Listed building records provide an indication of the special architectural or historic interest of the listed building which has been identified by its statutory address. The description and additional information provided are supplementary and have no legal weight.

These records are not definitive historical accounts or a complete description of the building(s). If part of a building is not described it does not mean it is not listed. The format of the listed building record has changed over time. Earlier records may be brief and some information will not have been recorded.

The legal part of the listing is the address/name of site which is known as the statutory address. Other than the name or address of a listed building, further details are provided for information purposes only. Historic Environment Scotland does not accept any liability for any loss or damage suffered as a consequence of inaccuracies in the information provided. Addresses and building names may have changed since the date of listing. Even if a number or name is missing from a listing address it will still be listed. Listing covers both the exterior and the interior and any object or structure fixed to the building. Listing also applies to buildings or structures not physically attached but which are part of the curtilage (or land) of the listed building as long as they were erected before 1 July 1948.

While Historic Environment Scotland is responsible for designating listed buildings, the planning authority is responsible for determining what is covered by the listing, including what is listed through curtilage. However, for listed buildings designated or for listings amended from 1 October 2015, legal exclusions to the listing may apply.

If part of a building is not listed, it will say that it is excluded in the statutory address and in the statement of special interest in the listed building record. The statement will use the word 'excluding' and quote the relevant section of the 1997 Act. Some earlier listed building records may use the word 'excluding', but if the Act is not quoted, the record has not been revised to reflect subsequent legislation.

Listed building consent is required for changes to a listed building which affect its character as a building of special architectural or historic interest. The relevant planning authority is the point of contact for applications for listed building consent.

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Printed: 18/06/2024 09:30