Mexico City urban development. 18th-century map (North at left) of urban improvements made to Mexico City when it was part of New Spain. The Spanish title (upper left) opens 'Iconographic plan of Mexico City', and names the mayor Ignacio Castera. Improvements included better paving, lighting, and public health infrastructure. The colour-coding shows the condition of streets and houses, and also highlights the drainage system. This map was published in 1794, for the 52nd viceroy of New Spain Juan Vicente de Guemes, 2nd Count of Revillagigedo (1740-1799). A key is at left, with a scale and the map-maker's name Manuel Ignacio de Jesus del Aguila.