The Monastery of St. Michael on the Heiligenberg (Saints" Mountain), was a branch of the nearby Lorsch Abbey. The ruined complex that can be seen today was built beginning in 1023. Within the nave are traces of the Roman temple of Mercury. The monastery was abandoned in the 16th century.
The first mention of the monastery is in the Lorsch codex, from the 12th century, which dates the founding of the monastery to 870. No remains of an earlier monastery have been found, so this might have been merely an estimate of the founding.
References:The Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.