The first time we visited Barcelona, we were only able to see the outside of La Sagrada Familia, the Antoni Gaudí basilica that’s been under construction since 1882, because tickets to view the inside sell out well in advance. So for our second visit, I did all of the research and bought the tickets for the tower we wanted to climb inside months in advance. And then it was raining like CRAZY the day we went, so the towers were shut down. 
But who needs views of the city when the inside of the church looks like this?!
Photo taken at: Sagrada Família