San Juan is the capital city of the Argentine province of San Juan in the Cuyo region, located in the Tulúm Valley, west of the San Juan River, at 46 m (151 ft) above mean sea level. San Juan is known in the paleontological community for the extraordinary rock formations in places like the Ischigualasto National Park, 330 kilometers form the city, also called the Valle de la Luna and the Quebrada de Ullum Dam, at 18 km from the city. An integral attraction to the province is its large Triassic period fossil record, believed to be one of the largest in the world.