A sinuous rille at the foot of the Apennine Mountains on the Moon, also known as Rima Hadley, at +25° lat., 3° E long. It was formed early in the history of the Moon as a giant lava channel 80 km long, 1500 m wide, and 300 m deep. The plain to the east of the rille was the site of the Apollo 15 landing in 1971.

http://apollo.sese.asu.edu/LIW/20071114.html

http://commons.wikimedia.org/wiki/File:Apollo_15_Hadley_Rille.jpg