U 11 is the Rundata designation for a runestone that is located near the ruins of the old king's dwelling at Alsnö hus near Hovgården on the island of Adelsö in Sweden.

This runestone style is characterized by slim and stylized animals that are interwoven into tight patterns.

The animal heads are typically seen in profile with slender almond-shaped eyes and upwardly curled appendages on the noses and the necks.

Håkon is believed to be the reigning king Håkan the Red, who is generally accepted as ruling during the 1070s.

This would be consistent with the runic text, which using the word kunungi or kunungr, Old Norse for "king."