Mulhacen at 3482 metres is the highest peak in mainland Spain. It can be climbed throughout the year but is normally snow covered between December and April inclusive. The ascent can be done in a long day from either above Capileira or the Sierra Nevada ski station to the north west.
Better to take two days and stay overnight at the guarded Poqueira Refugio. Here there are beds, blankets, meals and drinks. This way the mountain can be traversed and a much finer mountain experience can be had.