The Alhambra was the palace of the Moorish kings of Spain, located in the city of Granada. The full name in Arabic is
(Al Kal'at) Al Hamra, The Red (Castle). The first fortress was built on the site in the year 889, and it was expanded into a royal palace in the 14th century by Yusuf I, the Sultan of Granada. The red refers to the red clay used in the building. Today the Alhambra is a UNESCO World Heritage site. You can read more about the Alhambra in this
Wikipedia article.
For people who are interested in learning about Moorish Spain, I can highly recommend the historical novel
Leo Africanus by Amin Maalouf. The first part of the novel is set in Granada in the 16th century.
The image below shows an
architectural detail from the Alhambra:
