The Loch of Spiggie was historically a voe (Shetland Dialect: fjord or inlet) in which a sand bar formed, cutting off the sea.[1] It is considered "the only moderately large loch" in the South Mainland of Shetland, and is the fourth longest loch in Shetland. It is roughly rectangular, with the longest dimension approximately north–south, and the maximum width is almost 0.5 miles (0.8 km);[3] its area is roughly 1 km2.
The Loch of Brow is a smaller loch, about 0.25 km2 in area, lying to the south-east of the Loch of Spiggie, into which it outflows.[3]
The remains of a broch can be found on a small island in the loch. It used to be accessible by a number of stepping-stones which formed a "rough causeway"; however, these now lie 2 feet (0.6 m) under water. The remnants of a circular hollow approximately 8.5 metres (28 ft) in diameter can be seen, which is thought to have been the interior lining of the broch. A small portion of an outward-facing wall was excavated at the north end that suggested the broch's walls may have been between 3.5–4.0 metres (11–13 ft) thick.[4]