Apart from the gardens the outside of muslim buildings are often inconspicuous while the insides are abundantly decorated. The Alhambra is probably one of the finest examples of that, some rooms have every inch of space decorated with incredibly intricate stone and plasterwork. The pictures give some idea of the level of detail but to be in the alhambra and see room after room of it really blows you away. There used to be a lot more even but much got destroyed over the years by wars and christian rulers that seemed not to care too much for this Moorish legacy.