After a long period of controversy and debate that involved neighbours, local associations and City Hall, a decision has finally been made regarding admission to Park Güell: on October 25, 2013 the new rules governing access to a portion of the park took effect. The area affected by the new regulation is called 'monumental', and includes the Plaça de la Natura, the Escalinata del Dragón (Dragon's Steps) and the Sala Hipòstila (Hypostyle Hall). The rest of the park remains open to the public as usual. If you live in Barcelona, you may still get in for free, depending on your barrio.
If you are a resident of Can Baró, Salut, Carmel, Coll or Vallcarca-Penitents, you'll have free access to the park once you get a card from the City Council that is personal and non-transferrable. You can order your card on the Ajuntament website, by calling 010, or at the Oficines d'Atenció Ciutadana of Gràcia (Plaça de la Vila de Gràcia, 2), Horta (Lepant, 387) and Plaça de Sant Miquel.
If you don't live in any of these areas, you have to join the Gaudir+Barcelona club to get free access to the 'monumental' area. And to do that, go to the Oficina d'Atenció Ciutadana in Plaça de Sant Miquel with your local ID card or passport, and then go back seven days later to pick up your card. The card gets you the chance to book one free entry per day, and there are 100 entries per hour available.
So you don't live in one of the designated neighbourhoods and you don't want to sign up for the Gaudir+Barcelona ('Enjoy Barcelona more') or you're visiting and don't have time to get one, these are your options: pay the new admission fee of €8.50 (€6, reduced) for access to the 'monumental' zone (€7.50 – €5.25, reduced – if you get tickets in advance via Park Güell's website). Tickets are on sale at the box office machine outside the park and in the Lesseps and Vallcarca metro stations. You can buy up to nine tickets per person; entry is limited to 400 people every half hour.
As for the schedule, the 'monumental' area is open 8:30am to 6.15pm or 7pm in autumn-winter, and 8am to 8.30pm or 9.30pm in summer. Consult the park's website for exact timetables. The rest of the park operates regular hours from 5am to midnight.