If you head south along the coast for 23 kilometers towards Allinge-Sandvig, one of the most attractive resorts on the island, you'll pass by Hammeren Lighthouse. 

Strategically placed on a rocky plateau to the southwest of the lighthouse are the ruins of Hammershus Castle, built around 1250 for protection against marauding Danish kings. 

The fortress was violently fought over on several occasions and then sadly used as a quarry until placed under a preservation order in 1822. Magnificent views beckon from the adjacent cliffs.