Novelty architecture, also called programmatic architecture or mimetic architecture, is a type of architecture in which buildings and other structures are given unusual shapes for purposes such as advertising or to copy other famous buildings without any intention of being authentic. Their size and novelty means that they often serve as landmarks. They are distinct from architectural follies, in that novelty architecture is essentially usable buildings in eccentric form whereas follies are non-usable, purely ornamental buildings also often in eccentric form.