Replying to Panama

Looking to see if anyone has ever been to Panama and what I should try to do if I make it down there.

I am planning on stopping there with a long layover after a month of working in Costa Rica. The layover could last for a few days depending on how much I want to do/where I want to visit. I am trying to see a little bit of the country on a low budget while also being able to relax. Open to ideas for sure!

At the moment I am planning on being there from July 26th to the 31st and staying at Lunas Castle in Casco Vieja.

Thanks for helping me out.