Fort Vechten was constructed between 1867 and 1870 as part of the so-called Nieuwe Hollandse Waterlinie (The 'New Dutch Water Line') to defend the cities of the western Netherlands from overland attack.
The history of Vechten dates however back to the Roman times. The Romans, who apparently chose the spot because it controlled a side-arm of the Lower Rhine, built their castellum by the year 4 AD, and possibly named it after that river, Fectio. This fort was quite important from time to time as a supply-base for the invasion of Germany. It attracted the local population as well, which came to settle in the vicus at either end of the fort. The castellum was most likely abandoned by the late 3rd century, when the Roman Empire faced crisis after crisis. However, the main reason that the army never returned may well have been because the access to the fort silted up, which caused it to become land-locked, with all the ensuing logistical problems. The neighboring castellum at Trajectum/Utrecht may have supplanted it as local fort. Today there is a reconstructed Roman watch tower.
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.