Park GuŽll in Barcelona is a wonderfully historic park that was initially built in the early 1900s. The park is filled with stunning artwork and architecture designed by Gaudi. It does cost extra to go in to see most of the sculptures, so we decided not to do that.
But for free, you can see incredible panoramic views of the city and around the park, which is what we did. Their website has recommended routes around the park but we decided to just explore on our own and see what we could find. The park also has lots of picnic benches. There are no cafes, so I would recommend taking your own food and water. Keep in mind that the park is huge and there is lots of walking involved!