Located in the heart of Las Merindades, in an area of rough, uneven land and rolling hills, forming a sharp contrast with the sharp outline of the Sierra de Tesla mountain range at the southern end of the valley. The capital of Las Merindades, the town was founded to mark the northern boundary of the kingdom of Castile.

The centre is perched on the highest point, surrounded by a wall and protected by the imposing fortress built by the Velasco family.

In the 12th century the Jewish quarter was located outside the town walls, and access to the Christian quarter was via a gate that closed at dusk.

Declared a Historic Site, it boasts various monuments such as the Church of Santa Cruz, the Passage around the Wall and the Poor Clares Convent.