We have visited San Juan, Puerto Rico a few times and here are some of our favorite places and recommendations in the area (in addition to ones linked below):

Restaurants :

-Condal Tapas

-SOCIAL @ Condado Ocean Club

-La Casita de Rones

-Ladi's

-Barrachina

-La Vergüenza Viejo San Juan

-Bistro Café

-Anita Gelato Condado

-Gustos Coffee Co.

Sightseeing:

-Isla Verde Beach

-Condado Beach

-Kayaking/Paddle Boarding at Laguna del Condado

-Distrito T-Mobile (Entertainment, Dining & Shopping)

-Museo de Arte Contemporáneo de Puerto Rico

-Calle Cerra

-Ron del Barrilito Rum Distillery

Historical Sightseeing:

-Castillo San Felipe Del Morro

-San Juan National Historic Site

-Castillo San Cristobal

-Museo Casa Blanca

-Museo de las Americas

If you want to venture out of the San Juan area:

-El Yunque National Park

-Luquillo Beach & Kioskos

-Boat excursion to Icacos or Culebra islands

-Museo del Tabaco

-Museo del Cafe

-Waterfall Rappel & Zip Line Rainforest Excursions

-Cueva del Indio Natural Caves

Condado Vanderbilt Hotel