St Michael's Isle, popularly referred to as Fort Island, is noted for its attractive ruins. There is evidence for human activity on the island from the Mesolithic period onwards and there are two ancient buildings on the island. Both are in a state of ruin and closed to the public, though there are a number of walks which allow visitors to explore the surroundings.
St Michael's Chapel, a 12th-century chapel, is on the south side of the island. This Celtic-Norse chapel was built on the site of an older Celtic keeill.
The island is the site of two great battles for the control of the Isle of Man in 1250 and 1275, when England, Scotland and the Manx were fighting for control of the island. The Manx won the first battle, but 25 years later they lost control to Scotland.
Derby Fort, a 17th-century fort, is at the eastern end of the island. It was built by James Stanley, the 7th Earl of Derby and Lord of Mann in 1645, during the English Civil War, to protect the then busy port of Derbyhaven.References:
Easter Aquhorthies stone circle, located near Inverurie, is one of the best-preserved examples of a recumbent stone circle, and one of the few that still have their full complement of stones. It consists of a ring of nine stones, eight of which are grey granite and one red jasper. Two more grey granite stones flank a recumbent of red granite flecked with crystals and lines of quartz. The circle is particularly notable for its builders' use of polychromy in the stones, with the reddish ones situated on the SSW side and the grey ones opposite.
The placename Aquhorthies derives from a Scottish Gaelic word meaning 'field of prayer', and may indicate a 'long continuity of sanctity' between the Stone or Bronze Age circle builders and their much later Gaelic successors millennia later. The circle's surroundings were landscaped in the late 19th century, and it sits within a small fenced and walled enclosure. A stone dyke, known as a roundel, was built around the circle some time between 1847 and 1866–7.