National Palace of Sintra
The National Palace of Sintra, topped by its unmistakable pair of giant white cone-shaped chimneys, is the best-preserved medieval royal palace in Portugal and sits right in the heart of Sintra's old town. Kids love spotting the painted swans and chattering magpies on the ceilings, the shield-covered Coats of Arms Room, and the enormous kitchens under those 33-metre chimneys, all decorated with one of the world's finest collections of Mudéjar glazed tiles. The visit follows a one-way route through the royal rooms with some stairs and uneven floors, so it works best with a baby carrier rather than a stroller. Plan on about an hour to an hour and a half — an easy, walkable stop before heading up to Pena or the Moorish Castle.