Its maximum depth is 51 m. There are a number of little lakes scattered in the mountains and its canyons that show the action of the glacier activity of the Quaternary.

Along with numerous streams and the luxuriant and varied vegetation in every level, the park possesses high aesthetic and landscape value.

Woods of oak coexist with birch, alder, hazel, willow, ash, rowan, chestnut, holly and yews along with large extensions of scrubland (broom).

[4] The Park Interpretation Centre is located in the restored monastery of San Martín de Castañeda, a medieval building that belonged to Cistercian monks.

In winter, from Monday to Friday it is only available to organised groups, who may have a guide to show the park, opening to the general public on Saturdays and Sundays.