The Vembūtai Hillfort, located 1.8 km west of Lake Lūkstas and near the Domantas Stream, is a unique historical monument in Samogitia. Its slopes reach up to 13 meters in height in places, and the entire area is covered with trees and shrubs, adding to the hillfort's distinctive beauty. To the west, there are views of a deep cliff with a stream flowing at the bottom. It is believed that this site was home to the Vykintas Castle mentioned in the 13th-century Hypatian Chronicle, and nearby was the town of Vykintas.
Archaeological investigations reveal that remnants of fortifications, former barricade locations, and gate fragments have survived at the hillfort. Near the castle area, there is a manually dug water reservoir
that may have played a significant role in the castle's defense. There might also have been burial sites or even astronomical observation locations nearby. The strategic position of the hillfort among rivers, lakes, and swamps provided the castle with natural protection, making it one of the strongest defensive sites in the region. Due to its size, the Vembūtai Castle could have housed a larger military garrison than the nearby Medvėgalis, Burbiškiai, or Plinija castles. These sites were connected by roads, and causeways were constructed across fords and lakes to ensure safe passage.
It is believed that the Battle of Tverai mentioned in 1251 may have occurred in this area, near the Vembūtai Castle.