Park Güell is often described as one attraction, but it is really two: a large public park that is free to enter, and a smaller, ticketed "Monumental Zone" that contains most of Gaudí's best-known mosaic work, including the dragon fountain and the tiled serpentine bench.
What's free
The wooded paths, viewpoints over the city, and outer gardens of Park Güell are open to the public at no charge, with no ticket required.
What requires a ticket
The Monumental Zone — the colorful mosaic terrace, the Hypostyle Room with its forest of columns, and Gaudí's house-museum — is ticketed with timed entry, and capacity is limited per slot.
Getting there
Park Güell sits on a hill above the city center; most visitors arrive by metro to Lesseps or Vallcarca and walk up, or take a bus route that stops closer to the entrance.