This site is the result of a speleological phenomenon which involves the collapse of the central part of the hill, leaving only the extreme sides visible. These sides contain holes that are nothing more than the remains of the cave that once existed on this hill.

A river that is also known as Ega river. It starts in the municipality of Ansião and flows to the Mondego river. It crosses th ruins of the roman town of Conimbriga along a canyon. The upper part of the river has no water during a large part of the year.