Calavera

First ascent by Franciso Aguado in 1974. According to Cesar Castro, in his book Pedriza. Historias de 32 sendas de la vertical, Franciso went to El Yelmo on a Saturday with the intention of climbing a documented route.  By the end of the first pitch he realized he was in the wrong route but he had no longer a chance to descend. Since he was alone and could not use his rope anymore, he kept going up following natural features like dikes and cracks. He made it to the top alive.

The description below does not coincide exactly with the route as described by Cesar Castro and after P2 it is unlikely to be the line that Franciso followed.  The description here takes what seems to be a common way to climb la via Calavera.

P1- Start on a right facing dihedral. The first anchor can be seen from the ground.

P2- Traverse to your left following a horizontal crack and after 40ft climb up to connect with an obvious dike and follow it until you find an anchor. 

P3- Keep going left until the dike ends and reach for the curved crack to your left. It has a horn shaped end. Look for an obvious black crack to your left and setup an anchor under it.

P4- Climb the black flaring crack and you will get to a nice garden ledge with a dead tree. 

P5- (Optional. Not shown in photo) Climb the wall and continue on easy friction to the top. Build your own anchor.

If you are looking for more detailed Beta look in the comments below.

Descent: To the climbers left, find your way down through slabs. You can continue your downclimb all the way to the ground through what is known as the Valentina descend. Alternatively, you can also rappel using anchors from the many friction routes that exist. If you choose to rappel, a 70 meter rope will make your life easier. 

The start of the route is very distinct. A nice right facing dihedral with some gorgeous oak trees at its bottom. The dihedral connects with a left leaning system of dikes that crosses a good portion of El Yelmo.  As you look to  the South face of El Yelmo, find the two obvious butresses. Via Calavera is to the left of the butress on the right.  The cluster of trees at its base should also help locating the start.

This is not a sport climb. Carry a set of cams up to 3.5. The left traverse in P2 and P3 has long unprotectable stretches and the black crack in P4 is difficult to protect. This climb should not be scary for anyone solid at 5.6. If you are breaking into 5.6, it will test your nerves.