Ansgar monument, Stone memorial in Björkö, Sweden.

The Ansgar monument is a stone memorial on Björkö island with a large granite cross structure positioned on an elevated point. From this location, it overlooks the surrounding Baltic waters and the site of the former Viking settlement of Birka.

The stone was erected in 1834 to mark the place where Archbishop Ansgar carried out his first Christian mission to Sweden around the year 829. The monument stands on the grounds of an ancient fortress that had served as a major trading center since the 8th century.

The monument is a ring cross, a cross enclosed in a circle, raised in 1834 for the thousandth anniversary of Ansgar's arrival. It stands inside the hillfort Birkaborgen on Borgberget, where the missionary is said to have preached. Visitors today see the cross on the fortress rampart above the Birka archaeological area.

The monument is reachable via marked paths from the nearby Birka Museum, and regular boat services operate from Stockholm to the island during summer months. The site is best visited in fair weather to fully enjoy the views from the elevated location.

The cross is a ring cross (ringkors), a cross enclosed in a circle, standing on the crest of Borgberget inside the hillfort known as Birkaborgen. It was raised in 1834 for the 1000th anniversary of Ansgar's arrival at Birka, which places the commemoration in 834 rather than the 829 often cited for the mission itself.