Āraiši Lake Castle is located in the settlement Ayrashi, which is 7 km south of Cesis. The castle is a reconstruction of the castle drevnelatgalskogo water. Buildings ancient Latgalians 9th century managed to reconstruct, based on the remains of wooden structures and various ancient objects found here during archaeological excavations.

Borough Ayrashi - one of the few in the country, where they found the remains of a mammoth. Lake Ayrashi in the past was much larger. Now an area of ​​about 30 hectares, maximum depth of 11 meters. This lake district in ancient times was the natural appearance of the so-called "lake locks." Ayrashsky Castle is the first among the most extensively studied locks of this type, and therefore had the idea of ​​the reconstruction of the castle and the opening of a museum under the open sky.

Visitors to the castle lake Åraißi often wonder why this pile of wooden structures called lock. In the summer the water barrier can be regarded as a kind of protection against invasion in the winter, when the water in the lake is frozen, these wooden houses from attack nothing could protect. However, in ancient times, the climate in the area where the castle is located today, was a little warmer, and winter the lake froze and if, then very briefly. Therefore, in the winter, the lake was also a protection for the settlements. Therefore archaeologists call these buildings castle.

Interest in the ruins of the castle Åraißi appeared in 1876, when Earl Cesis K.-G. Sievers opened the castle as a monument, while believing that the remains of the Stone Age raft. Later, cited different hypotheses about the origin of these buildings and figuring out what they actually are. However, excavations for confirmation of a hypothesis, nobody spent.

In the period from 1959 to 1964. during the examination of underwater archaeological sites in the lakes edge in Latvia were found the remains of another 9 settlements. Similar to those that were found on Āraiši lake. It became clear that it was possible to open a new category of archaeological sites. To carry out large-scale studies have chosen Āraiši Lake Castle. The studies were conducted from 1965 to 1979 under the leadership of J. Apals.

As a result of the excavations, it became clear that the lacustrine settlement was established in 9-10vv living on it the largest of the ancient tribes of the Latvian community in Latgale. The foundation houses preserved almost completely, partially preserved remains of wooden buildings. For the study, scientists castle sank to the bottom with an aqualung. Remains of buildings covered with a thick layer of silt. It has been found not only to wooden structures, but also a variety of antiques: pottery, vessels and others.

Over the entire period of the archaeological site was found about 150 structures. The castle itself was a complex of buildings located on a rectangular timber flooring. The castle consisted of 5 rows Qurna cottages and outbuildings, which were located on the perimeter of the site in 4 rows. Between dwellings streets were wide and a half to three and a half meters. Around the castle were covered with log walls, to protect him. From coast castle connected the bulk dam. It is supposed that the castle was inhabited by different sectors of society, as evidenced by results antiques and found homes that vary in size and scope.

What remains of the castle came under the water, it explained very easily. Previously, the level of water in lakes was significantly lower than today. However, in the 10th century, in the northern hemisphere, a period of high humidity with frequent downpours. As a result, the water level in the lakes rose quickly. Water conserved buildings, and thus the remains have survived. Museum Åraißi lake castle was founded in 1983. Today it hosts a variety of festivals and events.