• Under-10s go free on the high wall and the Dos Milenios de Artillería guided visit; buy tickets at the information point by Santa María del Castillo church
• Park outside the walls: non-residents can't drive or park inside the walled town, and parking around it is free, including the municipal lot on Calle Tahona (8am to 9pm)
• Castle closed for now: the Castillo de los Mendoza is temporarily closed, so plan the day around the walls and the exhibition

Buitrago del Lozoya is a walled town on a loop of the Lozoya river, with medieval walls declared a national monument in 1931. Kids can climb onto the high south wall and clock tower, see siege engines and medieval weapons in the Dos Milenios de Artillería exhibition, and walk the low river wall for free. The Museo Picasso holds works the artist gave his friend Eugenio Arias, the town barber.