Fuerte de San Salvador, Coastal fort in Sanlúcar de Barrameda, Spain.

Fuerte de San Salvador is a small quadrangular bastioned fort built of ashlar stone between the dunes at the mouth of the Guadalquivir, between Bajo de Guía and Bonanza. Its walls, entrance remains, embrasures and two sentry boxes survive; inside were a guardhouse, storerooms and a terreplein with gun ports.

Built around 1626 by order of King Felipe IV to protect the port of Bonanza from piracy, the fort was designed by Jusseppe Gómez de Mendoza, master of the fortifications of Cádiz, during the time of Manuel Alonso Pérez de Guzmán, 8th Duke of Medina Sidonia. In 1645 it passed with Sanlúcar to the Spanish crown. In 1810, during the Peninsular War, it served as the command center for French troops defending the mouth of the Guadalquivir.

Locals have called it El Castillo de la Pantista since the early 20th century, when an elderly woman and her family lived inside the ruins. Dressed in black with a headscarf, she startled passers-by on the beach path, and the nickname stuck.

The fortress remains are freely accessible from Bonanza beach or via a walking path from the Barriada de Los Marineros neighborhood. Visit during clear weather when access paths are dry and visibility is good for viewing the structure.

The fort contained only four artillery positions, which limited its defensive capabilities and contributed to its early abandonment as a military structure.