A ruined church on the west coast of Unst in Shetland, Lund Kirk (also known as St Olaf's Chapel) lies a quarter-mile (0.5 km) northwest of Lund and dates from the 12th C., or earlier, most likely built for the occupants of the Viking settlement nearby. Built on an older foundation, the roofless building is of Celtic style and comprises a simple rectangular structure, measuring 14.5m (47 feet) by 6.8m (22 feet), with walls which are as much as 1.4m (4½ feet) in thickness. One of the window lintels represents the re-use of a Pictish symbol stone, with a fish or serpent carved on it. Inside the church is the modern burial enclosure of the Mouat family. The church is a Scheduled Ancient Monument and has been B-listed since 1971, in recognition of its importance as the best preserved of Shetland's Pre-Reformation chapels.
The graveyard, now enlarged, is still used and includes a pair of 16th C. Hanseatic gravestones. There are four Viking crosses nearby.