Around 800 AD, a chapel is said to have been built on the site of current Saaleck Castle. The origins of the castle remain unclear. It was first mentioned around 1030 by a historian from the nearby Homburg, which was being extensively expanded at the time.
Significant expansions were made in the 13th century. Abbot Heinrich von Erthal (1249–1261) completed the fortifications, adding ditches, walls, and battlements. The neck ditch was deepened, and the shield wall was reinforced. Over the following centuries, the castle was continuously worked on. Even Ulrich von Hutten once paid 50 guilders to renew a wooden bridge over the southern neck ditch.
Originally, Fulda's southernmost stronghold played an important role in the region. The castle was strategically located and was significantly strengthened during the time of Abbot Marquard I.
After the Thirty Years' War, Salentin von Sintzig rebuilt the castle as his retirement residence. According to his reports, the castle was in a very ruined state at the time, with large stones being taken away by locals for their own construction purposes. From 1644 to 1667, he meticulously rebuilt the entire complex. Before the Peasants' War, the castle had lost its military importance and had fallen into ruin. It had not suffered significant damage from wars or fires until the outbreak of the war, when it was suddenly occupied and devastated by rebels.
About 100 meters below the castle lies the upper end of the chapel's way of the cross from the Altstadt Monastery.
Today, the castle, or Schloss Saaleck, is protected as a landscape-defining historical monument.
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.