Sithun

Sithun, the ancient place where Odin according to Ynglinga saga settled when he arrived to ancient Svitjod.

By Snorri Sturluson said to be Sigtuna in the province of Uppland, Sweden.
Also the name of the town founded by Olof Skötkonung at Mälaren around 1000 AD.

See also Ubsola, the ancient Uppsala.