Hawaii, United States
Tantalus is an extinct cinder cone in the southern Ko'olau Range on the Hawaiian Island of O'ahu. It also has a summit crater, Tantalus Crater. The cinder cone formed after the demise of Ko'olau Volcano, during a time of rejuvenated stage volcanism in southeastern O'ahu that also formed Punchbowl Crater, Diamond Head and Koko Head. Tantalus overlooks the modern city of Honolulu, which is built on top of Tantalus cinders.
The southern slope of Tantalus was bombed in Operation K, Japan's unsuccessful second attack on O'ahu, which took place March 4, 1942.
Today, Tantalus is a popular hiking destination.