With around 300 inhabitants and a surface area of 679 hectares, Archsum (Frisian: Arichsem) is one of the smallest towns on the island and is located in the east, on the road from Keitum to Morsum.         

"Archsum" means "Settlment of Arke or Erke". The first recorded mention of Archsum, as “Arxum”, was in a decree of 1462 in the financial register of the Bishop of Schleswig. Excavations in the 1930s revealed that there had been a settlement in the area since the Neolithic period. At Mootjis Küül on the Nössedeich (a dyke) is the 5000 year old passage tomb Merelmerskhoog. Sometimes you can still spot the odd dwelling mound, for example the Firstklent. Archaeologists dug in Old Archsum between 1969 and 1974 and found that Archsum was the Troy of the North. They found Stone Age evidence and uncovered a settlement that had survived for almost 2000 years as well as a village that had existed between 700 and 1000 A.D. In 1860 the last remains of Archsum Castle were carried away.

The town has belonged to the municipality of Sylt East since 1970. Archsum is an contemplative, peaceful place, characterised by the old courtyards scattered through the area. The landscape is made up of meadows criss-crossed by creeks, and is considered to be a fishing heaven in summer and a haven for ice skaters in winter. Archsum is still a very pristine place, and the old language of Sylt, Söl’ring, can still be heard here today. Particularly worth a visit are the 5000 year old burial tombs, which look like large boulders at low tide.