El Camino Real de Tierra Adentro (English: The Royal Road of the Interior Land), also known as the Silver Route, was a Spanish 2,560-kilometre-long (1,590 mi) road between Mexico City and San Juan Pueblo (Ohkay Owingeh), New Mexico (in the modern U.S.), that was used from 1598 to 1882. It was the northernmost of the four major "royal roads" that linked Mexico City to its major tributaries during and after the Spanish colonial era.
In 2010, 55 sites and five existing UNESCO World Heritage Sites along the Mexican section of the route were collectively added to the World Heritage List, including historic cities, towns, bridges, haciendas and other monuments along the 1,400-kilometre (870 mi) route between the Historic Center of Mexico City (also a World Heritage Site on its own) and the town of Valle de Allende, Chihuahua.