Lying 5 miles (8 km) off the Fife coast, the Isle of May is the largest of the islands of the Firth of Forth. It is 1½ km long and ½ km wide and amongst naturalists is noted for its colonies of seabirds, its migrant birds and its colony of grey seals. Designated a national nature reserve in 1956, it is now recognised as an important seabird research centre.

The island is accessed during the spring and summer when a regular boat service operates from Anstruther and Crail to the landing at Kirkhaven. Weekly stays are possible in the Bird Observatory by prior arrangement.
Close to the Kirkhaven landing stand the ruins of the Chapel of St Aidan which are all that remain of a priory built in the 12th century and dedicated to the Christian missionary who was killed on the island by marauding Danes in AD 875. The Isle of May was an important religious centre until its monks moved to Pittenweem in the 16th century, but the island remained inhabited until the early 18th century.

In 1636 Alexander Cunningham built a lighthouse beacon, the first permanently-manned lighthouse in Scotland and in 1844 a subsidiary 'Low Light' was built on the east side of the island. During both World Wars the island was under military occupation and in 1989 the Main Lighthouse became fully automated prior to the ownership of the island passing from the Northern Lighthouse Board to the Nature Conservancy Council, now Scottish Natural Heritage.