THREE CASTLES OF BELLINZONA, Switzerland: Bellinzona has always occupied an important geographic location in the Alps. Several key alpine passes meet in the area, making it a key trading center. Much of the modern fortifications date from the period of construction in the late 15th century. Castelgrande is located on a rocky peak with a series of fortified walls that protect the old city & connect to the Montebello. The third castle (Sasso Corbaro) is located on an isolated rocky promontory.