from Labna, a Mayan city in Mexico, 9th - 10th century.
Labna's Arch is a good example of the corbelled arch developed by the Mayan architects and builders. The wall containing the arch was one side of a court that was surrounded by buildings.
In a corbelled arch the stones of both sides are successively laid so as to overhang the stone below until the two sides meet. The interior of the arch is then worked into a smooth surface.
Photo: Kohichi Hotta