The history of Welzheim reaches back to the time of the Roman Empire. Around the year 160 AD the Romans founded a colony and two forts there; linguists reconstructed their Latin name as (Castra) Valentia on the base of the town's medieval name Wallenzin first mentioned in 1181. In 1980, for the 800th anniversary of the founding of the city, the eastern part (Ostkastell) of the ruins was reconstructed, and in 1993 an archeological park was founded on the site. It contains replicas of Roman stone monuments and explanatory plaques about Roman Welzheim. The western part of the fort was built over through the years.
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.