Trelleborg - Viking ring fortess. Zealand, 980 AD

There are four gates into the fortress, and the gates are connected to each other by wooden blocked streets, which intersect at the center of the fort.

These wooden blocked streets also divide the fort into 4 equal parts.  Tree ring dating of the timber used to build the houses from Trelleborg (near Slagesle) shows that the houses here were built of wood harvested around 980 AD. This is during the reign of Harald Bluetooth (Harald Blåtand).