You can stroll along Port of San Juan for relaxing water views when you're in San Juan Antiguo. Hotels.com travelers also say the area is full of friendly people and has lots of nice beaches. If you carry on walking you'll get to Pier 1, San Juan Ferry Dock, and Pier 4 for some more water views.
Luquillo Beach is located 25.7 mi (41.3 km) from the center of San Juan, why not stop by during your stay. Catch the sunset by the shore at Playa Fortuna, just a short walk away.