Tibidabo Amusement Park - High above Barcelona is a beloved amusement that's been fun for kids and teens since the 1920's. Everyone in the family will enjoy getting twirled and spun, along with amazing panoramic views of Barcelona. Don't miss the Museu d'Automats, a collection of mechanical toys from the 19th century.
From the lookout (mirador) you'll have the best views of Barcelona (even better than Montjuic Park), 360 dregrees in all directions, with the sea and mountains in the distance. There are snack bars at the park, or but this is also a great place to bring your picnic lunch.
Part of the fun is getting to Tibidabo. The quickest, easiest way to get to the park is to take the T2 "Tibibus" from the bus stop at the east side of Plaça de Catalunya (the bus will be full of local teens and families, it's a festive and fun ride). Or from Pl. de Catalunya, take the train Line 7 to Av. Tibidabo. Then hop on the old-fashioned electric blue tram (Tramvia Blau), and transfer to the funicular that takes you up the mountain to Tibidabo. (If the Tramvia Blau isn't running, there's a regular bus to goes from the train to the funicular.)
Allow plenty of time to enjoy Tibidabo. The bus is the most direct, and it's a half hour ride one way winding up the mountain. A great option is to take the bus up, and the funicular and tram down.