Website of Barcelona Tourism
http://www.barcelonaturisme.com/wv3/en/
Barcelona Card
http://www.barcelonacard.com/en
The Barcelona Card is the city’s official visitor card which lets
you explore, visit and discover Barcelona at your leisure and offers big savings
on visitor attractions.The Barcelona Card includes free admission and discounts at the
city’s main visitor attractions.
It is recommendable to buy tickets on-line in advance to visit the most frequented sights.
Sagrada Familia: https://tickets.sagradafamilia.org/site/SagradaFamilia/product/11-guided-experience/type/1?_ga=2.81442263.153357980.1494409571-274611959.1494409538
Park Güell: http://www.parkguell.cat/en/buy-tickets/