Nordborg Castle

Nordborg Castle sits on the southern shore of Nordborg Lake with rectangular buildings that have white walls and red-tiled roofs built on a stone foundation. The layout consists of connected wings that form a unified compound housing both residential and educational spaces.

The fortress was founded in 1151 by King Svend III as Alsborg and protected the coast from attackers. It was later renamed Nordborg to reflect its position as the northern fortress compared to nearby Sønderborg Castle.

The castle serves as a boarding school where students live and study within its historic walls. This use shapes daily life at the site and connects the old buildings to contemporary educational practices.

The grounds are generally accessible on most days, though the buildings inside are often closed to visitors due to school operations. Check ahead to confirm that tours are available since the school takes priority over visits.

The original name Alsborg references the Wendish raids that were a major threat to coastal communities in medieval times. This historical connection to defence against eastern raiders is often overlooked in favour of the castle's later story.