There are multiple palaces and monuments to visit in Sintra and we chose Park and National Palace of Pena given its unique style which is very different from any other European palaces we have visited. The architects of this palace indulged every whim and fantasy to create a magical world of fairytale palaces surrounded by enchanted forests. The choices of very bright colors , yellow, pink, and purple, make the palace look like a real-size version of a Disney toy castle. If you are a fan of minimalism and elegance then this might not be your favorite place to visit. But otherwise, you will have a blast exploring the design details of this crazy mashup of styles: a mock medieval castle with islamic domes, Moorish geometric tiles, and Disney-esque pink towers.
Pick 1-2 sites to visit rather than hitting a few if you have only one day in Sintra. Each site is large in area and there are so many details within that they are worth exploring at a slow and leisure pace.