Fortaleza de San Lourenzo

Spain, Spain

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Fortaleza de San Lourenzo, also known as Castillo de San Lorenzo, is a 16th-18th century Spanish colonial fortress located at the mouth of the Chagres River on Panama's Caribbean coast, overlooking the entrance to what became the Panama Canal.

Built starting in 1595 by order of King Philip II to protect the vital trade route transporting Peruvian gold across the isthmus to Spanish Atlantic ports, it featured designs by Italian engineer Bautista Antonelli with massive stone walls, batteries, cisterns, tunnels, and a strategic hilltop position above a reef.

Repeatedly attacked by pirates like Henry Morgan in 1670 and British forces under Edward Vernon in 1740, it was rebuilt multiple times until largely abandoned mid-18th century, later serving as a prison before UNESCO recognition as a World Heritage Site in 1980 alongside Portobelo's fortifications.