Alūksne Castle was built in 1342 by Teutonic Knights on the largest of the islands in the Lake Alūksne and called Marienburg (after Mary, the mother of Jesus). The first castle was constructed by the Landmeister Burkhard von Dreileben. It was part of a major reinforcement of the Eastern border of Livonia, the same year another major castle nearby (in Vastseliina) was founded as well.
The initial castle was built of wood. Later, the outer walls were constructed of fieldstone and the convent house of bricks. The plan is in many ways similar to that of Viljandi Castle, including the convent building with a flanking tower. The outer wall originates partly from the same time as the convent house, partly from later periods, notably from the time of the political tensions in early 16th century. The main gate, protected by two round towers, is also of late medieval origin. Later, at the end of 17th century, the castle was supplied with ravelines and ramparts.
The strength of the castle was repeatedly proven by repelling a number of attacks in 16th century. Alūksne was captured by the troops of Ivan IV of Russia in 1560 during the Livonian War. It was incorporated into the Polish-Lithuanian Commonwealth in 1582. The town became part of the Swedish Empire in 1629.
After the fall of the Old Livonia, the castle remained habitable. It was finally destroyed 1702 in the Great Northern War by its Swedish garrison to avoid falling in the hands of Russians. The ruins remained largely untouched. Today, it houses an open-air scene and forms a part of a recreational area of the Pils (Castle) Island.
References: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.