Carlos María de Castro (Estepa, 24 September 1810 - 2 November 1893) was a Spanish architect, engineer and urban planner. He created the plan of the urban expansion (Ensanche) of Madrid.[1] The New Plan of Madrid was commissioned in 1857 and adopted in 1860.[2] It was inspired by some technical aspects of Ildefons Cerdà's early studies and plans for the extension of Barcelona.[3] But unlike Cerdà who sought to avoid social segregation, Castro proposed functional and social zoning.[3]