This volcanic butte at the end of Mill Avenue has many names; the original inhabitant Hohokam Indians regard it as ʼOidbaḍ Doʼag, the city of Tempe as 'Hayden Butte' after the city's founder, and ASU students affectionately know it as 'A Mountain'. Regardless of the nomenclature, everyone can agree that the butte provides a nice hike with some beautiful views of Tempe and its environs once you reach the top. In addition to some great exercise, on the way you will see ancient petroglyphs from the aforementioned Hohokam, native wildlife and the massive letter 'A', which celebrates the nearby university.