Why go
The city's outline gives the monuments their purpose. El Morro guarded the bay entrance, San Cristóbal defended the land approach, and La Fortaleza began as a harbor defense before becoming a government residence. Read the old city as a connected defensive landscape, then look beyond it for present-day San Juan.
The full story
Spanish colonists established the town on the harbor in the early sixteenth century. From the old city, the entrance to San Juan Bay could be watched and defended. That setting still explains the position of Castillo San Felipe del Morro at the western tip of the islet and Castillo San Cristóbal on the eastern side of the fortified district. La Fortaleza, near the bay, belongs to the same early defensive story even though its role changed. The capital did not stay within its old walls. Neighborhoods grew across the islet and onto the main island, so the San Juan of the forts is only one part of the municipality. Old San Juan is the clearest place to see the city's colonial layout, with its plazas and masonry buildings. The wider city is where that history meets later architecture, cultural institutions and everyday urban life. Keeping those scales separate helps when planning a visit: a walk among the forts is a focused historic outing, while seeing Santurce or Hato Rey calls for a different route.