The Arecibo Observatory tour in Puerto Rico currently cannot be booked. I heard second-hand that this may be because its full already, but typically they can charter more buses. I’ll be checking again this week to see if it opens up.
The “That Yoda Guy” shop was really cool when we made an unofficial event of it a couple years back and walked there from the port with a JoCo group. I still have a really sweet signed poster on my wall here that I got there.