Kayaking:
kayak in bioluminescent bay , besides Bio Bay, there are other kayak tours. (BTW, there are 3 bioluminescent water sites in Puerto Rico, make sure to see one if moon allows)
Ziplining:
zip lines in Puerto Rico
Porta Coeli one of the oldest churches in Western Hemisphere
If take a break from the sun or raining out, the
Museo de Arte in Ponce is worth a look.
Puerto Rico's
roast pork highway
One of the best beaches in all of Puerto Rico is
Luquillo just don't go on weekends or a holiday when it will be packed with locals. Luquillo is an old coconut plantation, there's been times where I'm standing in the water, sun on my back, sipping on a cocos frios, looking back at a cloud shrouded El Yunque. Looks like a scene from Bora Bora.
A plus about Luquillo is there is a strip of food stalls (some very plain basic & others full restaurants). Some excellent food can be had.
One of the finest (if not the best) beachfront resort & dining room is
The Horned Dorset Primavera. You can still dine at resort if not a guest.