Ruins of León Viejo is a World Heritage Site in Nicaragua. It was the original location of León. It is the present location of the town of Puerto Momotombo in the Municipality of La Paz Centro of the Department of León. It is administered by the Instituto Nicaragüense de Cultura (Nicaraguan Institute of Culture).
León Viejo was founded on June 15, 1524 by the Spanish conquistador, Francisco Hernández de Córdoba, who was decapitated at the town's Plaza Mayor (Main Square) in 1526 by governor Pedrarias Dávila, his Lieutenant.