Martyrs of Christ the King Cathedral, Piedras Negras  The Martyrs of Christ the King Cathedral () Also Piedras Negras Cathedral Is a Catholic temple that serves as the cathedral of the city of Piedras Negras to the northeast of the state of Coahuila in Mexico, near the border with the Texan city of Eagle Pass. Located inside the Technological Residential, it is one of the modern jewels from the city. In March 2008, the Cathedral "Mártires de Cristo Rey", home of the Diocese of Piedras Negras, was headed by the Apostolic Nuncio Christophe Pierre, the Cardinal of Monterrey Francisco Robles Ortega and seventeen bishops, in addition to the presence of the Hierarchy of the Catholic Church in Mexico.