Very close to the summit, on the east side, is the Ventisquero de la Condesa, an area with water emanations that constitutes the source of the Manzanares river, and where great thicknesses of snow accumulate in winter.

To the north of the summit there is a small mountainous branch, called Loma del Noruego, which separates the valleys of Valsaín, to the west, and Lozoya, to the east.

Near its summit, at an altitude of 2000 meters and on its southeastern slope, is the Ventisquero de la Condesa, a place where there are several water springs that are the source of the Manzanares river.

Cayetano Enríquez de Salamanca in his book (now out of print) Por la Sierra de Guadarrama (page 107), a person who was careful with the toponymy of the mountains, described the situation of the four Guarramillas: ".... the Guarramillas, a group of four summits about which there is an evident toponymic confusion, since some of them are called Guarramas, although this name does not exist (already in the 14th century Alfonso XI called them "Guadarramiellas")...".

With the progress and improvement of current measuring equipment, the elevations cited by Cayetano E. de Salamanca are those corresponding to 2179 m, 2227 m, 2258 m, and 2248 m of the 1st, 2nd, 3rd and 4th Guarramillas according to the IGN maps in their latest editions.

Specifically, the 20th stage, which took place on Saturday, September 18, 2010, started from San Martín de Valdeiglesias and arrived after almost 169 km with four scoring difficulties, one third category, two first category and the summit of the Bola del Mundo of special category, at 2250 m.[4] The winner of this stage and therefore the first winner at the top of the Bola del Mundo was Ezequiel Mosquera, Galician cyclist of the Xacobeo-Galicia team, but then the UCI annulled his victory for an alleged case of doping, although months later the National Court annulled the sanction, the victory is still invalidated by the UCI; entering the finish followed by 1 second by the winner of the 2010 Vuelta, the Italian Vincenzo Nibali.