National monument (United States)
Monuments assigned protected status by presidents of the US
.jpg/500px-Petroglyph_National_Monument_Aerial_(52260985771).jpg)
In the United States, a national monument is a protected area that can be created from any land owned or controlled by the federal government by proclamation of the president of the United States or an act of Congress. National monuments protect a wide variety of natural and historic resources, including sites of geologic, marine,...