The Varbola Stronghold was the largest circular rampart fortress and trading centre in Estonia in the 10th-12th centuries. The first record of Varbola is written by Henry of Livonia, who mentions the Castrum Warbole being besieged in 1211 for several days by Mstislav the Bold of Novgorod. The conflict was resolved with a payment of seven hundred Marks.
During the Livonian crusade Livonian Brothers of the Sword invaded the territory and the people from Varbola asked for the terms of peace. The terms offered by Livonian Brothers of the Sword were accepted by Varbolians, but later the people of Varbola became the subjects of the King of Denmark. On the basis of the Danish Census Book the estate surrounding the Varbola trading center remained a possession of the Lode family, nobility of Estonian origin at the time. The Varbola stronghold lost its importance only in the second quarter of the 14th century, after having played in important part in the anti-Christian and anti-German St. George's Night Uprising of 1343.
In the 16-17th centuries the stronghold was used as a cemetery. The first known fort plan dates from 1786 and was drawn by Ludwig August von Mellin. Archaeological excavations at the site have been undertaken in 1938-41, 1953 and 1974. Among the archaeological finds were dice made of bone.
Parts of the ruins of the 580 metre long and 8-10 metre high limestone wall of the fortress stand still this day. The long gateways with multiple gates were built to defend the entrances. In these sections higher defensive towers were erected. There was a 13 metre deep well in the middle of the fortress and the territory held about 90 structures with furnaces for accommodation built with limestone floors and foundations.
Reference: Wikipedia
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.