The Sierra Nevada Mountain range in the province of Granada is 100% worth a visit. No matter who you are, if you like the outdoors, you will find what you are looking for (skiing, hiking, climbing, stargazing, etc.)
The Sierra Nevada has the third highest peak in Europe, called the Mulhacen, which rises over 3,450 metres (11,400 ft). During the summer the Sierra Nevada serves as one of the places where the locals and tourists from around the world escape the dry heat. How? By climbing the mountains. Temperatures at the bottom may be over 40°C (over 100°F), but the top of the mountains are quite cold. Make sure to take at least a long-sleeved shirt or sweater with you when ascending. Even though the temperature drops, the amount of sun increases (along with the UV reaching your skin). Don’t forget to take some form of sunblock. You don’t want to look like a lobster served in some of the restaurants in the Sierra Nevada villages.
If you want to see more than just desolation and mountains, the Siete Lagunas (Seven Lagoons) route takes hikers around 7 lakes that are located between the Mulhacen and the Alcazaba (the third highest mountain of the range) and offer a stark contrast to the mountains as one hikes along green meadows. Note: during the summer of some very dry years, the lakes will evaporate.
If you are a hiking pro (or a new hiker who also is a masochist), there is a route called the Vereda de la Estrella Loop. It goes along the three highest mountains in the range (Mulhacen, Veleta, and Alcazaba) and then returns through one of the deep valleys. This route was created to access the Estrella copper mine. It is a feat of engineering and offers stunning views that you shouldn’t missed!
Here are some more photos: