The Cathedral Island (Polish: Ostrów Tumski, [ˈɔstruf ˈtumski], German: Dominsel, [ˈdoːmɪnzəl]) is the oldest part of the city of Wrocław in south-western Poland.

The Cathedral Island in Wrocław is one of the few remaining places in Europe where a lamplighter lights the gas street lamps every evening.

[2] Archaeological excavations have shown that the western part of the Cathedral Island, between the Church of St. Martin and the Holy Cross, was the first area to be inhabited.

After taking control of the area and waiting for the political situation in Silesia to stabilize, he chose the Cathedral Island as his new capital.

An interesting indication of the special status of the island was a ban on wearing any headdress by men, effective even on Tumski Bridge beyond the border pole of this small "ecclesiastical nation" (the law also applied to royalty).