The tower got its name after the legendary founder of the castle. The origin and age of the castle is still in the realm of speculation.
The oldest written note comes from the year 1370, but it is almost certain that the castle had been founded much earlier, somewhen in the second half of the 13th century, during the reign of King Přemysl Otakar II. According to the latest research, which is, however, not final, since archaeological research has not finished yet, the castle boasted one angular and four round towers. Its fortification system was strengthened with moats and a bailey wall.
Gradually, the importance of the citadel decreased, moreover it was badly damaged by the fire in 1532. Since then the castle was used for other purposes; a part of it was for example turned into a local magistrate’s jail. Between the years 1612 and 1613 the castle was rebuilt into a brewery (brewery cellars). In the second half of the 19th century, in connection with a radical modernisation of the factory, some parts of the castle underwent further alterations. As late as 1908 the whole eastern wing of the castle had to be pulled down because of the expanding brewery. Kotnov Tower is therefore the only preserved part of the castle. Those who climb to its top will be rewarded with a beautiful view of the town and its surroundings.
The only preserved town gate, called Bechyňská, is adjoined to the tower. Unlike the castle, it was treated much better, and has survived almost in the same state as in the 15th century when it was built. At the end of the 19th century it underwent a thorough reconstruction. Its Gothic interior hosts an exhibition called The Life and Work of Medieval Society.
The exposition inside the gate is closed due to reconstruction - it will be open again in 2019.