The Mexico City Cathedral is a massive structure constructed of basalt and gray sandstone. Its walls are thick and reinforced with thick iron chains for earthquake resistance. The cathedral is laid out in a traditional Latin cross pattern, with a central nave and two side aisles. The central nave is a long, rectangular structure, 110 meters long from north to south and 55 meters wide from east to west. The altar, deep within the central nave, is covered by a classic Renaissance dome. The vault features numerous ornate arches and reliefs. The side aisles, intersecting the central nave in a cross-shaped pattern, house numerous smaller altars and seven chapels. Some of these chapels have been subsequently renovated and altered by artists from various artistic schools.