Maungawhau erupted 28,000 years ago from three separate craters. The last eruptions from the southern crater filled the northern two, leaving the single dramatic bowl visible today. The Māori name means 'mountain of the whau tree,' after the native plant that once covered its slopes. The English name came from Governor William Hobson, who chose it to honour George Eden, the 1st Earl of Auckland and his superior naval officer. Both names survive in the mountain's official dual title, a recognition formalized in a 2014 Treaty of Waitangi settlement. The cone sits within the Auckland volcanic field, a collection of some 50 volcanoes scattered across the isthmus, each one the product of a single eruptive episode. Maungawhau is the tallest of those that sit on the narrow land bridge between the Waitematā and Manukau harbours.

The summit's trig station, which became the reference point for surveying Auckland's suburbs, was built on a platform constructed with an unlikely helper: Prince Alfred's elephant. The animal, brought to New Zealand during a royal visit, hauled materials up the slopes and was reportedly rewarded with lollies, buns, and beer. It is a detail almost too whimsical to be true, but it captures the layered absurdity of colonial Auckland, where Polynesian terracing met Victorian surveying met exotic wildlife. By the early 20th century, inmates from nearby Mount Eden Prison quarried stone from the maunga for road-building projects, altering the cone's profile in ways that are still visible.

From the 1950s onward, the New Zealand Post Office operated VHF radio communications from two buildings on the peak, each with its own antenna farm. One housed transmitters, the other receivers. In the 1960s, technicians staffed the site five days a week because the vacuum tubes wore out constantly under high power loads. Taxi companies and delivery firms relied on the facility for mobile communication with their vehicles, making the volcanic summit an unlikely node in Auckland's commercial life. But the crater also attracted another kind of use. In 1973, artist Bruce Barber staged his Mt Eden Crater Performance inside the bowl, an experimental piece involving a blind art master and drummers. During the mid-1980s, Philip Dadson organized annual winter solstice celebrations in the same space. The crater's acoustics, its sense of enclosure, its separation from the city pressing in above, made it a natural amphitheatre.

Maungawhau was the principal pā of Huakaiwaka, the eponymous ancestor of the Waiohua people, and remained important to Waiohua from the 17th century until about 1740. The cone was extensively terraced, with defensive ditches carved around four areas of the maunga. In 1840, Ngāti Whātua gifted 3,000 acres of isthmus land to European settlers for the new capital, and Maungawhau marked the southern boundary of that gift. The 2014 Treaty of Waitangi settlement returned ownership of 14 tūpuna maunga, including Maungawhau, to the Ngā Mana Whenua o Tāmaki Makaurau collective. The Tūpuna Maunga Authority now administers the mountain, and Auckland Council manages it under their direction.

In 2019, the 1926 Spanish Mission-style tearoom near the summit was converted into Whau Cafe and the Te Ipu Kōrero o Maungawhau Visitor Experience Centre, which tells the geological and Māori cultural history of the maunga. The following year, boardwalks were opened around the crater rim to protect the pā tūāpapa, the ancient terraces, and the rua kūmara, storage pits for sweet potatoes that sustained the community centuries ago. Vehicles have been banned from the summit since 2015. The walk up takes about fifteen minutes, and the reward is one of Auckland's most complete panoramas: the Sky Tower to the north, Rangitoto Island floating in the Hauraki Gulf, and the deep green bowl of Te Upu Kai a Mataaho at your feet, still keeping whatever secrets Mataaho hid there.