- Where
- San Juan, Puerto Rico
(a US territory) - Coordinates
- 18.47° N
66.11° W (the old town) - Founded
- 1508 (Caparra); moved 1509;
named San Juan 1521 - City walls
- 42 ft high; about three-quarters remain
- World Heritage
- 1983 (La Fortaleza and
San Juan National Historic Site) - Getting there
- Luis Muñoz Marín International (SJU),
in Carolina - Best visited
- Outside hurricane season
(1 June to 30 November) - Advisory
- Domestic (US territory): no State
Department advisory applies
Blue-grey stones underfoot, slippery after every shower, and houses in parrot colours with iron balconies and ferns growing out of the gutters. At the far end a great stone fort stepped down to the sea, with an enormous lawn in front where the wind did as it liked. I sat in a little domed stone lookout on the corner of the wall and watched the ocean arrive, over and over.
The short answer
Old San Juan is the historic walled district of San Juan, the capital of Puerto Rico, Wikipedia records. Juan Ponce de León founded the first settlement, Caparra, in 1508; in 1509 it moved to a site then called Puerto Rico, and in 1521 it received its formal name. The city walls are 42 feet high, about three-quarters of them still stand, and one city gate survives, the Puerta de San Juan. In 1876, 24,000 people lived inside the walls in 926 buildings on 25 hectares. The district was listed on the National Register of Historic Places on 10 October 1972 and became a National Historic Landmark District in 2013; La Fortaleza and the San Juan National Historic Site were inscribed together as a UNESCO World Heritage site in 1983.
Why it's worth knowing
A fort that was taken once. Castillo San Felipe del Morro was begun in 1539 on the orders of Charles V and reached its present form in 1787, Wikipedia records; it rises 43 metres (140 feet) above the Atlantic shoreline in six levels. Sir Francis Drake attacked San Juan with his fleet in 1595 and failed. In 1598 George Clifford, Earl of Cumberland, attacked by land and took the fort, the only time El Morro was taken in battle; his force left in November, weakened by dysentery. In 1797 a British force of 7,000 to 13,000 men under Ralph Abercromby was repelled, and the fort’s last fight was a US Navy bombardment on 12 May 1898. The broad lawn in front, once covered with ball fields, hospitals and a golf course, was cleared back to its eighteenth-century look in 1992.
A governor’s house and a cathedral. La Fortaleza, built between 1533 and 1540, is the oldest executive residence in the Western Hemisphere, Wikipedia records. San Juan Cathedral, which the article says is considered the oldest cathedral in the United States, holds the tomb of Juan Ponce de León. Beside El Morro, the colonial cemetery of Santa María Magdalena de Pazzis holds, among others, Pedro Albizu Campos and José Celso Barbosa. The small eighteenth-century Capilla del Santo Cristo de la Salud was saved from demolition in the twentieth century.
A drink with two birthplaces. The piña colada, which Puerto Rico proclaimed its official drink in 1978, has two claimants, Wikipedia records: the Caribe Hilton Hotel says its bartender Ramón “Monchito” Marrero created it in 1954, and the Barrachina restaurant credits the Spanish bartender Ramón Portas Mingot, in 1963. This entry names both and settles nothing.
The field notes
The other fort, and the walk along the wall
Castillo San Cristóbal, the old town’s other great fort, was built in 1783, and the San Juan National Historic Site article calls it the largest fortification ever built in the New World. Its Garita del Diablo, the Devil’s Sentry Box, stands apart from the others and is not open to the public. The National Park Service has administered the forts, the city walls and El Cañuelo, a small fort on Isla de Cabras that is not open to the public, as the San Juan National Historic Site since 14 February 1949; the site counted 1,027,264 visitors in 2022. Below the southern wall, the Paseo de la Princesa, a promenade of 400 metres, gives access to the best-preserved stretch of the walls and its famous sentry boxes. The Park Service closed the Paseo del Morro trail in June 2023 because of a water leak through the wall; its archived notice gives no reopening date, and the park’s alerts page lists nothing now.
The blue stones
The old town’s narrow streets are paved in blue cobblestones, Wikipedia records, without saying where the stones came from. Tour guides and travel writers tell them as iron-smelting slag brought over as ships’ ballast, but they disagree about where the slag came from and when the streets were laid, giving dates from 1784 to the 1890s (indexed); this entry found no archival source for any of it, and repeats it only as the story told on the street.
A garita on the city wall above San Juan Bay.
Photograph: Joseacaraballo · CC BY-SA 4.0
The city wall on San Juan Bay.
Photograph: Ovidio Soto via Unsplash · Unsplash licence
Old San Juan's blue paving stones after rain, December 2010.
Photograph: Eric Pancer · Old San Juan's Blue Brick Roads I · CC BY 2.0 · cropped
Colourful facades with iron balconies in Old San Juan, 2024.
Photograph: Zixi Zhou via Unsplash · Unsplash licence · cropped
- Go to the big fort first thing in the morning, before the lawn fills up.
- Sit in one of the little domed lookouts on the wall and watch the sea for as long as a sentry would. (The list stood watch beside me, reported nothing approaching, and asked to be relieved by noon.)
- Order the pineapple drink and ask who invented it. Then ask somebody else. (Two answers, both very firm. The dispute has moved into the list, where I am keeping well out of it.)
- People live behind the painted doors. Keep the steps and doorways clear, and ask first before taking a picture of anyone at their own window.
- Admire the blue stones of the old streets, which are lovely and, after rain, extremely keen to sit you down.
A garita. The small stone sentry boxes on the walls of El Morro, San Cristóbal and the old city, called garitas, are bartizans: small turrets that stand out from a fortification’s wall, from which a sentry kept watch, Wikipedia records. Its article on the San Juan National Historic Site calls the sentry boxes along the Paseo de la Princesa famous; one at San Cristóbal, the Devil’s Sentry Box, is closed to the public. They are seen from the walls and the paths, and left as found.
Tally, in the marginTo me it looked like a pepper pot left on the wall by a giant, and I sat in it some time before I saw that it had a slit to look out of and a job to do. I begged its pardon, and kept watch properly for the rest of the hour.
Getting there
How to get there. By air to Luis Muñoz Marín International Airport (SJU), in the municipality of Carolina, the busiest airport in Puerto Rico, which handled about 13.6 million passengers in 2025, Wikipedia records; the old town is reached by the Baldorioty de Castro Expressway (PR-26). Puerto Rico is a territory of the United States, so flights from the US mainland are domestic. The old town is best seen on foot.
When to go. The Atlantic hurricane season, as defined by the US National Hurricane Center, runs from 1 June to 30 November; the drier months outside it are the more settled time to visit. Island-wide power cuts have happened more than once in recent years, and Discover Puerto Rico, the island’s tourism board, has issued travel updates during them (indexed).
What to arrange ahead. As of 20 October 2026, the Park Service’s fees page for San Juan National Historic Site (updated 9 May 2023) gives $10 for adults, valid for 24 hours at both fortifications, with children 15 and under free; it accepts major credit cards and contactless payment, and no cash. No timed entry for the forts was found. Book rooms in the old town ahead in the winter season and on cruise days.
Safety. Puerto Rico is a US territory, so the State Department’s travel advisories, which cover other countries, do not apply. The National Hurricane Center posts forecasts in season.
Mark this place
Common questions
When was Old San Juan founded?
Juan Ponce de León founded the first settlement, Caparra, in 1508; it moved in 1509 to the site of today’s Old San Juan, in Puerto Rico, and received its formal name in 1521, Wikipedia records.
What is El Morro in San Juan?
El Morro, Castillo San Felipe del Morro, is the Spanish fort at the tip of Old San Juan, Puerto Rico, begun in 1539 and completed in its present form in 1787. It rises six levels, 43 metres above the Atlantic, and was taken in battle only once, by the Earl of Cumberland in 1598.
How much does it cost to visit El Morro and San Cristóbal?
The National Park Service’s fees page for San Juan National Historic Site, Puerto Rico (updated 9 May 2023), gives $10 for adults, valid for 24 hours at both forts, El Morro and San Cristóbal; children 15 and under are free, and no cash is accepted.
Is Old San Juan a World Heritage site?
Yes. UNESCO inscribed La Fortaleza and the San Juan National Historic Site, the forts and walls of Old San Juan in Puerto Rico, as a World Heritage site in 1983.
Why are Old San Juan's streets blue?
Old San Juan, in Puerto Rico, is paved in blue cobblestones. Tour guides describe them as iron-smelting slag brought as ships’ ballast, but accounts disagree on the source and the date, and this entry found no archival record to confirm either.
What is La Fortaleza?
La Fortaleza is the governor’s residence in Old San Juan, Puerto Rico, built between 1533 and 1540, and the oldest executive residence in the Western Hemisphere, Wikipedia records. It is part of the World Heritage site inscribed in 1983.
Where was the piña colada invented?
Two places in Puerto Rico claim the piña colada: the Caribe Hilton Hotel credits its bartender Ramón “Monchito” Marrero in 1954, and the Barrachina restaurant credits Ramón Portas Mingot in 1963. Puerto Rico made it the official drink in 1978.
Is Puerto Rico part of the United States?
Puerto Rico, where Old San Juan is, is a territory of the United States, Wikipedia records; flights from the US mainland land at Luis Muñoz Marín International Airport, in Carolina, the busiest airport in Puerto Rico.