Viking ring castle ruins

The Trelleborg near Slagelse on the Danish island of Zealand. Similar to the other Viking ring castles found so far, it was designed as an exact circle with two roads that crossed at right angles in the geometric center and led to the four gates with two always opposite to each other. In each of the four quarters stood four almost identical longhouses arranged in a square. The whole fortress may have supplied room for some 1,300 people. It was constructed near the year 1000.