The Tomb of Leonidas has an impressive edifice (12.5m × 8.30 m), probably dating back to the late 5th century BCE. It was made of massive limestone and its interior was divided in two connected chambers. The eastern chamber was 3.15 meters long, had the form of a pronaos (vestibule) and was ornate with columns. Until today, the use of the edifice has not been verified.It is believed to be a cenotaph, while many researchers share the opinion that it is the temple of Karneios Apollo.
Although there is no indication on the correlation between the temple and the legendary king of Sparta, according to local tradition and the travel writer Pausanias, the remains of Leonidas were transferred and buried there. It is because of this, that the locals believe it to be the tomb of Leonidas. Pausanias also mentions that annual games were hosted here to honor the memory of the Spartan king.
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.