The third image held no people, just a view of a small circular fort containing a large iron caldron.

A circular defensive fort, usually built of stone.

Fyrkat is the site of one of four circular Viking forts found in Denmark.

On the southern side of the common, the misnamed Caesar's Camp is what's left of a roughly circular earthen fort built in the .

Remains of Celtic circular forts and sanctuaries can be found all over the region.

A circular fort with a diam.

The townspeople constructed the circular fort day and night until it was completed.

(g) Tor of Craigoch circular fort with outer defences.

The Celtic circular fort at Otzenhausen is one of the biggest fortifications the Celts ever constructed.

The circular fort has a diameter of 210 metres, making it the largest of the hill forts known in Norfolk.