What are the most worthwhile things to do in Havana on a first visit?

The colonial core is organized around four plazas laid out over the sixteenth and seventeenth centuries: Plaza de Armas, Plaza de la Catedral, Plaza Vieja and Plaza de San Francisco de Asís. They sit within about fifteen minutes' walk of one another, and the lanes between them are the point as much as the squares themselves. Havana was established on this harbor site in 1519, and the street grid still follows the pattern that grew up inside the city walls.

The fortifications are the other half of the inscription, and they are not decorative. Castillo de la Real Fuerza, begun in 1558 and finished in 1577, stands at the mouth of the inner harbor and is among the oldest surviving stone fortresses in the Americas. Across the channel, Castillo de los Tres Reyes del Morro went up between 1589 and 1630 to guard the entrance. San Carlos de la Cabaña was built from 1763 to 1774, directly in response to the British capture of Havana in 1762 — a fort built because the last one had failed.

Beyond the World Heritage boundary, two set pieces define the modern city. The Malecón seawall runs about five miles along the Atlantic front and was begun in 1901. The Capitolio, completed in 1929, closes the view at the western edge of the old town. Both are free to look at and both reward a late-afternoon walk rather than a midday one.

The old city is built of coral limestone cut from the shoreline, and on a bright day the plazas throw back a hard pale glare while the side streets stay in deep shade — the buildings are tall enough and the lanes narrow enough that the two never meet. Across the water the forts sit on bare rock above the channel, exposed to the wind in a way nothing in the old town is.

Because the inscription covers a working residential district rather than a ticketed site, there is no gate, no single entrance and no closing time for the old city itself — but individual museums and forts inside it each set their own hours. The practical consequence is that your day is shaped by the harbor rather than by opening times: the forts are on the Casablanca side of the channel, and getting over and back is the fixed cost in any itinerary that wants both halves of the property.

• Early morning — Start at Plaza de Armas before the tour groups arrive; the booksellers set up here and the square is at its quietest before nine.
• Midday — Move inland to the Capitolio and the streets behind it, where there is more shade than on the waterfront.
• Late afternoon — Cross to El Morro and La Cabaña for the view back across the channel, with the sun behind you and on the old city.

For US travelers the constraint is legal rather than logistical: OFAC's general authorizations cover 12 specified categories of travel under 31 CFR 515.560(a), and a traveler relying on one is expected to keep records of the trip. The State Department's country-wide Level 2 advisory, dated May 7, 2025, asks for increased caution. Restoration work is continuous across the old city, and scaffolding on one or another of the four plazas is routine rather than exceptional, so a specific facade may be wrapped when you arrive.

The Havana when-to-visit question in this group covers the dry-season timing that makes a full day of this walking realistic, and the food and drink question explains the private-restaurant system you will be eating in between stops.