Mulhacén is the highest mountain in the Iberian Peninsula (3468m), it's part of Sierra Nevada.
It's not a difficult peak so can be climbed in a single day.

My group arrived on the Friday night at Hoya del Portillo where we spent a night bivouacking.
First time on Saturday morning we started the hike, and we reached the summit at 6pm without problem, walking quitly, our goal was to enjoy the hike.
We decided to sleep in the bare shelter at Caldera to the west. Small shelter and many people so we had to sleep on the floor again.
Next day, we came back at Hoya del Portillo in the noon and we returned to our home.

You can find many hikers, maybe if there weren't so many people around the summit it could be more enjoyable. Much better go in low or snow season.