This tower is one of the first things you see in Barcelona. However, in my case, it took me by surprise.
It was raining, so I had it in my mind to drive up the mountain and visit the Sagrat Cor church. However, the clouds created a thick blanket of fog, and it was difficult to see more than a hundred feet. As I stood outside the church, the clouds began to thin, and the tower appeared rather dramatically.
Here is a close-up view that T took with the telephoto lens fully extended. The tenth level is the observation deck, according to Wikipedia.
The tower sits atop the Tibidabo mountain and overlooks Barcelona. If I had Googled it, I would have known that it’s open to the public on weekends — something to add to my next visit.