Granada

The city of Granada is worth seeing on its own, but if you only have a day, then invest it in the Alhambra. It's best to buy tickets online in advance, to avoid queues and the risk of there being no more free entry. Arrive in the morning, it's easy to park right at the entrance. Expect strict controls - documents, tickets, frames.
If you have chosen to enter The Palace of Nasir (the heart of Alhambra) at a later hour, you have time to explore the Generalife (gardens) and the Alcazaba (Moorish castle) in peace.

What beauties await you?

If you have time for the city, look into the inner courtyards (patios). This architectural and very practical feature was brought here by the Arabs. You will really appreciate its cooling effect in the sultry summer. Some patios are accessible, you can usually find a restaurant in them and you can try a wonderful local custom. Granada is one of the last places where you get a free tapa when you order a drink.