Cast-iron architecture is the use of cast iron in buildings and objects, ranging from bridges and markets to warehouses, balconies and fences. Refinements developed during the Industrial Revolution in the late 18th century made cast iron relatively cheap and suitable for a range of uses, and by the mid-19th century it was common as a structural material (and sometimes for entire buildings), and particularly for elaborately patterned architectural elements such as fences and balconies, until it fell out of fashion after 1900 as a decorative material, and was replaced by modern steel and concrete for structural purposes.