Truman Annex Waterfront. With its touch screens, stunning photos, and roomy theater showing a short high-definition film about the Keys ecosystems, this educational center has become a hit with families. It's a fun way to learn about reef and mangrove habitats before or after an excursion. The newest addition is the Living Reef exhibit, which fetures a 2,500-gallon reef aquarium. Free admission and parking on-site.