Cieszyn, one of the oldest towns in Silesia, has had a Slav population (Golensizi tribe) since at least the 7th century. According to a modern legend, in 810 three sons of a Slav king – Bolko, Leszko and Cieszko, met here after a long pilgrimage, found a spring, and in their happiness decided to found a new settlement. They supposedly called it Cieszyn (cf. the verb for "to be happy"; Polish: cieszyć się, Czech: těšit se). This well stands in the ulica Trzech Braci (Three Brothers Street), just west of the town square. More scientific explanation for the name is that it's patronymic in origin, derived from the Slavic name *Ciecha or *Ciesza. The town centres on Castle Hill (Góra Zamkowa), where the oldest traces of settlement date back to the 6th or 7th centuries. The gród built on the hil