Built in 1930 and covering an area of 113 hectares the reservoir is currently 61% full, exactly the same as it was at this time last year.
La Pena collects water from the surrounding mountain range and forms a very picturesque lake.
Today was ideal for the Boxing Day walk, an attempt to burn off a few of the calories from yesterday.
No one else had the same idea however - we were the only people there!