Been there a few times. Go to El Yunque, the rainforest that's not far from San Juan, there's a waterfall you can climb around on and take a refreshing dip. If you can, take a day and drive up into the mountains, it is a rare chance to experience a Caribbean island that's safe and you're still on American soil. A dish you will see on menus called Mofongo Relleno is a must-try, it's green plantains with garlic and bacon that's mashed to form a crust for whatever meat or seafood and sauce they put inside. I'm envious, it's a fun place, don't know if I'll ever make it back there...please take pics.