c) Devils Tower

Devils Tower, declared the first U.S. national monument by Theodore Roosevelt in 1906, is a striking geological feature located in northeastern Wyoming. This massive rock formation, known for its sheer walls and columnar structure, rises dramatically from the surrounding landscape. Devils Tower is considered sacred by many Northern Plains tribes and is a popular site for climbers and tourists alike. Its unique and imposing presence has made it a symbol of the American West and a significant site for geological study and cultural importance.