The highlight of our trip to Spain was our visit to La Alhambra, on the south-eastern border of the city of Granada (here's a map of Spain). La Alhambra was the residence of the Muslim kings of Granada and contains beautiful examples of Islamic art and architecture.
A view of La Alhambra, perched on a hill overlooking the city of Granada (to the right)

Poppy, Grayson, and Sonny loved the fountains, waterfalls, streams, and ponds that are throughout La Alhambra
The architects of La Alhambra tried to cover every single space with decoration, no matter the size of the space. Most of the interior arches are false arches, with no structure; they are there only to decorate.
An intricately carved dome ceiling
Even the stone walkways had intricate designs
The view over Granada