Søby Volde – or ramparts – were possibly established by King Niels (1104-1134) as a fortification against foreign attackers.

The German expansion in the Baltic and several attacks by the Wends on the Danish population necessitated this type of castles. The castle functioned for approx. 150 years, but lost its significance before the end of the 13th century and quickly decayed.

The actual ramparts are still very well preserved, and the peak of the hill is 36 metres above sea level. Southwest of the fortification, Vitsø Nor, a cove that is now drained, stretched almost to the ramparts which consist of three main parts:

outer rampart to the north of the area. (ILLUSTRATION: Fyns Amts fotografi)

1. a main rampart with an almost trapeziod outline, provided with an outer rampart. 2. a double moat with an intervening, pointed rampart north of the main earthen works 3. a front castle with something that may resemble a semicircular