Spain: The Alhambra
The Alhambra in Granada is probably one of the most fascinating places we've been to. I HIGHLY recommended springing for a private tour. We very rarely book tours (or much of anything else for that matter) in advance of our trips. We like to wander and explore places without too much of a schedule. That said, the best part of the Alhambra is only accessible with a scheduled time. We tried booking tickets about a month in advance, but all times were sold out except for private tours — I'm so happy it worked out that way. We were able to walk through at our own pace, get around congested areas more quickly, and I could stop for photos as much as I'd like.
It's always been a bucket list item of mine, and it did not disappoint. The geometry, symbolism, and symmetry are a photographer's dream — I could have shot the light and shadows of this place for days!