Real Alcázar

The Alcazar is an amazing building. The ground floor is the original Moorish palace, while the first floor was built on top later by the Kings of Spain. This is the sort of place I can spend all day taking pictures in. Absolutely beautiful!

Great palace – amazingly detailed architecture.

often known by the plural Reales Alcázares (Royal Palaces)
One of the finest ancient building complexes in Spain.
Allow plenty of time to enjoy the gardens too.
Timetable
Wikipedia in English, and in Spanish
Entrance €5; free for retired, locals, students—formal id needed.