The district of Alt-Kaster is also known as the "Pearl on the Erft". Small alleys and alet gabled houses make up the charm of this medieval town.
The village of Kaster was first mentioned in documents in the 12th century. The buildings still standing today date from the 17th century. The historic town centre is surrounded by a town wall with two gates, the Agathator and the Erfttor.
Inside the city walls, markets such as the Ricarada Market and the St. Nicholas Market take place on a regular basis. Then cakes, waffles and other delicacies are sold through windows and the inner courtyards and gardens invite you to get together in a cosy atmosphere.
In the immediate vicinity of the town is the area with the Kasterer See lake, which was recultivated after the end of lignite mining. Alt-Kaster is the starting point of the family-friendly Werwolf hiking trail.