Old San Juan and visit the forts. You can buy a National Parks passport and have it stamped in the parks. Pretty neat. It was blistering hot when we went for Easter this year, but we enjoyed it. We stayed at a hotel in the Condado Beach area (San Juan Marriott Stellaris) awesome family hotel. We booked a snorkeling trip through East Island Excursions to Icacos island. It was about an hour ride from the hotel (they picked us up). It was amazingly beautiful. Near Icacos is the Palominitos Island where Pirates of the Carribbean was filmed. Sometimes the boat stops there, depends on weather I think. Highly recommend that trip. We were on the boat with the slide, and the kids LOVED it!