The Vikings had a stronghold at Aggersborg surrounded by an enormous rampart. Towering to the north of the rampart there is a church of Aggersborg, probably erected during the 12th century. An interesting illuminated inscription of runes can be seen on the walls of the nave and the northern chancel wall. The altarpiece dates back to 1598, but it wasn't placed in Aggersborg until 1934. The previous altarpiece can be seen on the northern wall of the nave. It pictures the founding of The Lord's Supper. There used to be family burial places behind the beautiful lattice.
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The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.