Things to do in Puerto Rico (for tourists coming for Hamilton)

I know there are some PR residents who are frequent posters on this message board, so I thought it might be fun to start a thread about fun things to do or see in Puerto Rico. During the next 3 weeks tens of thousands of mainland U.S. Citizens will be visiting PR to see Hamilton so please share any and all suggestions for activities outside of seeing Hamilton. Trip Advisor is great, of course, but it's no replacement for personal suggestions IMO.

There are travel sites that will probably be more informative than any posts here.

I second doing a tour of the rain forest. Depending on the paths you take there are some beautiful waterfalls.