Fuerte La Planchada, 17th century coastal fort in Penco, Chile.

Fuerte La Planchada is a stone fortress located on the coast of Penco that stretches about 65 meters along the shoreline. The structure has thick walls built from stone and features gun emplacements positioned to defend the Pacific waters below.

The fortress was built in 1687 under the orders of Governor José de Garro to defend the coast from corsair attacks during Spanish colonial rule. It later served as a prison holding political detainees during the Chilean independence movement.

The fort displays the coat of arms of Spain and Governor Garro's insignia, representing the Spanish military architecture of colonial South America.

The fort is accessible via Avenida Costanera and Línea Férrea street with local bus connections to nearby towns. The area is best visited in good weather when you can see across the bay and explore the surrounding coastline comfortably.

The Spanish coat of arms on the fort, quartered for Castile and León, was likely moved here later; historian Carlos Oliver Schneider and in part Frezier suggest it originally adorned the Governor's Palace in the city. Below it the motto "Plus ultra" can still be read.