Panorama over Trälhavet

Trälhavet is a bay in Stockholm's inner archipelago north of Resarö, south of Åkersberga and west of Saxarfjärden. The shipping lanes to Stockholm go from Saxarfjärdarna across Trälhavet through either Kodjupet or Oxdjupet.

The name Trälhavet, Trælahaff, is documented as early as the 15th century and may also have consisted of the word thrall meaning "slave", compare the desert name Grodhavet on Lake Mälaren.