La Fortaleza, a UNESCO World Heritage site and the official residence of Puerto Rico's Governor, offers a unique historical experience in Old San Juan. While the exterior and surrounding areas are generally accessible by foot, guided tours are typically required to explore the interior, providing rich historical context; solo visits are generally limited to the outer grounds and photo opportunities from the outside. It's generally open year-round, though access and tour schedules can be subject to official events or holidays, so checking in advance is advised. Visits are often free or low-cost, and a typical guided tour lasts about 30-60 minutes. Visitors should be aware of potential photography restrictions inside and can combine this visit with a wider exploration of Old San Juan's charming streets.