Cordova Island, also known as Isla de Córdoba, is not a true island, but is located on both sides of the current channel of the Rio Grande in El Paso and Ciudad Juárez, Chihuahua, Mexico. In 1899 the United States and Mexico dug a channel across the heel of the horseshoe-shaped peninsula to control the flood-prone Rio Grande, but left the original riverbed, which wound to the north around the island, as the international boundary. Thus the 385-acre tract was part of Mexico, though it lay north of the Rio Grande, for most of the twentieth century. During prohibition Cordova Island was a notorious haven for smugglers; it was almost completely surrounded by American soil, but lay outside the city limits of Juárez. The famous Hole in the Wall, a saloon and gambling parlor, flourished just a few yards from the border in defiance of United States and Mexican authorities, before it was finally torn down in January 1931. In 1963 the treaty that settled the Chamizal Dispute transferred 193 acres on Cordova Island to the United States in exchange for an equal area further downstream. In the 1990s the channel of the Rio Grande bisected the old island from east to west, and Interstate Highway 110 crossed it from north to south.