Located on the road into town, the Fortaleza San Fernando de Omoa, or El Castillo, as the locals call it, is open for tours daily (tel. 504/658-9167, 8 a.m.–4 p.m. Mon.–Fri., 9 a.m.–5 p.m. Sat.–Sun., US$2, guides are available for $5). Entrance includes a visit to the adjacent Museo de Omoa, which has small but insightful exhibits on the history of the area, an overview of the fort, and displays of antique guns and swords.
Fortaleza San Fernando de Omoa is undergoing restoration thanks to a loan from the Inter-American Development Bank, and excavated cannons and munitions are on display within its walls. The small souvenir shop stocks good-quality pottery and jewelry made from coconut shells.
The Caribbean coast of Honduras  was sparsely populated throughout the colonial era, making it an easy target for attacks by pirates, marauding Miskito Indians, and, later, the British Navy. Although pirate assaults began just a couple of decades after the Spanish started to colonize Central America, it was not until the mid-18th century that colonial authorities made serious efforts to combat the marauders and fortify their positions on the coastline.
As early as 1685, the Spanish recognized Omoa  as an ideal location for a fort — strategically situated on a deep, protected harbor between English settlements in Belize, the Bay Islands , and the Mosquitia. But distractions elsewhere, a lack of funding, and bureaucratic inertia combined to delay actual construction until 1752, when royal engineer Luis Diez de Navarro arrived with a plan for a massive triangular bastion.
Work on the fort was painstakingly slow. For a start, there was no adequate stone in the area; it had to be cut and transported from as far as 150 kilometers away. Even more dire was the lack of workers; disease and heat took a brutal toll on the conscripted Indians. Omoa became known as the graveyard of Honduras among the highland Indians, and able-bodied males fled their villages when they heard that colonial officials were coming to look for workers. Eventually, the crown brought in black slaves to finish the fort.
Finally completed in 1773, the fort was an intimidating sight. Two of the three sides were 60 meters long, while the ocean-facing base measured 25 meters. The walls were 6 meters tall and 2 meters thick. The complex overflowed with 150 pieces of artillery and was surrounded by a moat. Despite its daunting appearance, the fort was never particularly successful.
A combined British-Miskito force of almost 1,000 men, led by Commodore John Luttrell, took it in 1779, just six years after construction had been completed. After that inauspicious first defeat, the fort at Omoa  fell variously to Spanish royalists, Francisco Morazán’s forces, and, later, Guatemalan soldiers. Apparently easier to get into than out of, the fort was finally converted into a prison by the Honduran government in 1853.
In spite of its dismal record of defense, the fort is visually impressive, squatting ominously in the tropical heat a kilometer or so from the ocean. The Caribbean has receded in the years since its construction, leaving the fort standing amidst the fields and swamp between the Puerto Cortés  highway and the beach. It is undergoing a significant restoration thanks to a loan from the Inter-American Development Bank.