Ekornavallen is one of the richest prehistoric sites in Sweden. The earliest burials were made in the Neolithic period, 3000 BC. The 20 meters wide and two meters high burial mound is dated to Bronze Age (1800-500 BC). There are also lot of different kind of settings (like standing stones and stone circles) from the Iron Ages built between 0-500 AD.
The largest, and best known, of the Neolithic passage graves at Ekornavallen is one called the Girommen which according to early writers means the giant oven. It consists of sandstone slabs, but the mound which once covered the grave is entirely gone. Between the lower passage and the chamber proper lies a very large and thick slab, the "Key stone", resting on the passage stones. The grave was restored in the 1940s when a fragment of a chisel, some amber slivers and some ornate potsherds were found.
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.