Kids' Stuff, San Sebastián
Concierge.com's insider take:
If you've got wee ones in tow, you'll want to take the Funicular from Ondarreta beach up Monte Igueldo. The panoramic view of the city will wow them (and you), and there's a small amusement park with rides at the top of the mountain (34-943-210-564; www.donostia.org). Access to the park is included in the price of your funicular ticket (less than $5).
At the foot of the opposite mountain, Monte Urgull, is San Sebastián's Aquarium, with live piranhas, clown fish, and sharks as well as an enormous whale skeleton (1 Carlos Blasco de Imaz Plaza; 34-943-440-099; www.aquariumss.com).