The Park Güell is a public park system composed of gardens and architectonic elements located on Carmel Hill, in Barcelona. With urbanization in mind, the park was designed by Gaudi on the demand of Eusebi Güel. The park was built between 1900 and 1914 and was officially opened as a public park in 1926. In 1984, UNESCO declared the park a World Heritage Site.
This park is also a symbol of city for go there you can use the Metro, line green(L3), stations Lesseps or Vallcarca or the Bus urban, line H6, D40, 24 et 92.
The duration of the visit is around an hour for the free parts (the most important), a little parts is around 8euros for see a beautiful view of Barcelona and some arts of Gaudi. You also can go and see the Casa del Guarda which is one or two hours.