These are the Port Hills, known in Māori as Ngā Kōhatu Whakarakaraka o Tamatea Pōkai Whenua. They're called Port Hills because they sit between Christchurch and its port at Lyttelton. What you're seeing now is actually an eroded bit of the Lyttelton volcano, which blew its top millions of years ago.
The hills start over at Godley Head, run east-west along the north side of Lyttelton Harbour, and then keep going south, separating the city from the harbour. They stop near Gebbies Pass, at the head of the harbour. You'll find a bunch of summits here between 300 and 500 meters above sea level. These hills are super important for their geology, environment, and, of course, the views.
This volcano is one of two that formed Banks Peninsula about 12 million years ago. Māori settled this area in the 14th century. When Europeans arrived some 500 years later, these hills were a real challenge between the harbour and the planned settlement of Christchurch. They were so steep and rugged that getting across was tough. For about 17 years, from 1850 to 1867, most settlers used the Bridle Path, which was pretty steep, to get themselves and their things to the plains. Nowadays, there's the Lyttelton road tunnel and a separate rail tunnel connecting the port and the city suburbs. You can also cross the range by road via Evans, Dyers, and Gebbies passes, all linked by the Summit Road.
These hills have also seen some serious bush fires. In February 2017, fires burned for days, destroying over 1600 hectares of bush and nine homes. Then again in February 2024, another big wildfire started on Worsleys Road, burning about 700 hectares, destroying one home, and causing evacuations and a state of emergency.
The Port Hills are a big part of the central Canterbury landscape and you can see them for miles from the north and west. The height of the crest varies, being lowest at the eastern, or seaward, end. There are two main road passes from Christchurch: Dyers Pass, which is about 330 meters high and almost due south of central Christchurch, is the more prominent one. Evans Pass, around 200 meters high near the eastern end, usually connects Sumner and Lyttelton. It was closed after the 2011 Christchurch earthquake damaged Sumner Road on the Lyttelton side but reopened in 2019.
Between Evans Pass and Dyers Pass, there are several significant peaks. You can spot Sugarloaf at 494 meters by the television transmission tower on its summit. Then there's Mount Cavendish at 448 meters, and Tauhinukorokio / Mount Pleasant, which is the highest peak in the northern arc of the Port Hills at 499 meters. West of Dyers Pass, the hills curve south and get even higher, reaching 573 meters at Coopers Knob. From Coopers Knob, the crater rim drops down to Gebbies Pass, which is about 160 meters high. The hills south and east of Gebbies Pass are considered part of Banks Peninsula proper, not the Port Hills themselves.
Some Christchurch suburbs, like Cashmere, Mt Pleasant, Heathcote Valley, and Sumner, extend onto the northern slopes of these hills. Other parts are used for farming and forestry, and there are a lot of scenic reserves for recreation and conservation. These reserves started with an initiative by Christchurch councillor Harry Ell around the turn of the 20th century. In 1948, the Summit Road Scenic Society was formed to keep developing and maintaining these reserves.
The hills are a really important