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 Erfurt Synagogue was built c. 1094. It is thought to be the oldest synagogue building still standing in Europe. Thanks to the extensive preservation of the original structure, it has a special place in the history of art and architecture and is among the most impressive and highly rated architectural monuments in Erfurt and Thuringia. The synagogue was constructed during the Middle Ages on the via regia, one of the major European trade routes, at the heart of the historical old quarter very close to the Merchants Bridge and the town hall. Many parts of the structure still remain today, including all four thick outer walls, the Romanesque gemel window, the Gothic rose window and the entrance to the synagogue room.
After extensive restoration, the building was reopened in 2009. On display in the exhibition rooms is an collection of medieval treasures discovered during archaeological excavations. This includes 3,140 silver coins, 14 silver ingots, approx. 6,000 works of goldsmithery from the 13th and 14th centuries and an intricately worked wedding ring of the period, of which only two others are known to exist anywhere in the world. A mikveh (Jewish bath) has been excavated close by (13th/14th century). The Old Synagogue, the Small Synagogue and two Jewish cemeteries together form a network of historical buildings and sites which vividly portray the role of Jewish life in the history of Erfurt.