We were able to get tickets for this tour within 15 minutes of the tour. The tour lasts about an hour, and is in Spanish and English. The outside of the building, the lobby, and the views are gorgeous. The tour of the other floors of the building is pretty lackluster (unless you're big into architecture, but even then- not anything special on the inside to the average tourist), but it's worth sitting through it for the 360 views at the top. There are tiny balconies at the top that you can step outside to take pictures, and they take you to the very top and turn on the light house. Definitely worth an hour of your time for the views. There are quite a few very narrow stairs to get to the top, so note that if you can't walk up a lot of stairs it may be difficult. They do have an elevator at the top, but it only takes one person at a time.
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