Before coming to Bocas del Toro I spent a year working in San Jose, Costa Rica and was able to travel a lot on the weekends and see the country. My radius was not huge because I only had about 60 total hours for the weekend and the roads are terrible, but luckily the country is tiny. I had a flight a couple of weeks ago to Las Vegas for about $400 and went up by bus from Bocas a few days early to visit Arenal Volcano and stay at the Tabacon Resort and Spa, which I had done about 4 years ago and really enjoyed with my family.
The volcano is usually covered in clouds, but last time I was there we were able to get a great view of the whole cone for the two days we spent and actually saw glowing lava flows at night while we soaked in the thermal pools at Tabacon. The thermal springs area is very impressive, but man the water is really hot and it seems like every time I leave there I have some kind of rash, that could be from any number of activities though and I would still go back.