Alcázar of Seville

The Alcázar of Seville is one of the oldest continuously occupied royal palaces in the world, and it remains an official residence of the Spanish royal family to this day. Built on the foundations of an Abbasid governor's palace and transformed over centuries by both Moorish and Christian rulers, it is a place where architectural eras layer on top of each other in a way that feels almost impossible — Gothic chapels beside Islamic tiled courtyards, Renaissance gardens behind Mudéjar arched doorways. It sits in the heart of Seville's old city, next to the cathedral, and it is as essential to understanding this city as anything else you'll find here.

Visiting means wandering through a series of palatial rooms and open-air courtyards, each more elaborate than the last. The crown jewel is the Palacio de Don Pedro, built in the 14th century by Pedro I of Castile and decorated by craftsmen brought from Granada and Toledo — the tilework, carved stucco, and coffered ceilings here rival anything in the Alhambra. Beyond the palaces, the gardens stretch out in an almost dreamlike sequence of fountains, orange trees, hedgerow mazes, and lily-covered pools. The upper royal apartments are often open for a separate visit and give you a glimpse of actual royal furnishings and Flemish tapestries. Game of Thrones fans will recognize the Water Gardens of Dorne from filming done here.

Book tickets in advance — this is non-negotiable, especially in spring and summer when queues for walk-up visitors can be brutal and timed-entry slots sell out days ahead. The Alcázar is large enough that you'll want at least half a day, and the gardens alone can absorb an hour. Come early in the morning when the light in the tiled courtyards is soft and the crowds are thinner. The audio guide is genuinely useful here — the history is dense enough that some context makes the difference between overwhelmed and genuinely moved.