Alte Burg, 'The old castle', in Burgsinn is a moated castle owned originally by the Barons of Thüngen. In 1337, the Bishop of Würzburg granted the castle and all its possessions as a fief to Dietz von Tungden, who largely built the present castle between 1339 and 1342.
The wide moat surrounding the castle is fed by an underground spring. On the west side, a bridge leads into the castle, which has a trapezoidal layout with towers at its corners. The outer wall is made of rusticated sandstone blocks, while the rest of the masonry is rubble stone, and the southern residential building features timber framing on its upper levels.
The square northeastern tower includes a small elevated residence. A pointed arch door leads into the southeastern tower, which was completed in 1543 by Martin I von Thüngen. The southern wall has been significantly altered with inserted windows, and the round-arched gate at the southwestern tower was fitted with corbels.
The castle complex is dominated by a square, five-story, 22-meter-high keep (dating to the 12th century), constructed of rusticated stones.
The stone church of Gamla Uppsala, built over the pagan temple, dates from the early 12th century. Due to fire and renovations, the present church is only a remnant of the original cathedral.
Before the arrival of Christianity in Sweden, Gamla Uppsala was the seat of Swedish kings and a ceremonial site known all over northern Europe. The settlement was home to royal palaces, a royal burial ground, and a great pagan temple. The Uppsala temple, which was described in detail by Adam of Bremen in the 1070s, housed wooden statues of the Norse gods Odin, Thor and Freyr. A golden chain hung across its gables and the inside was richly decorated with gold. The temple had priests, who sacrificed to the gods according to the needs of the people.
The first Christian cathedral was probably built in the 11th century, but finished in the 12th century. The stone building may have been preceded by a wooden church and probably by the large pagan temple.