In Wellington the 1840 shoreline is marked in the pavement.

01 A quay two hundred metres from the water

Lambton Quay is the main shopping street of the centre, and its name comes from when it was, literally, the edge of the harbour. Today two blocks of buildings stand between the street and the water.

The 1855 Wairarapa earthquake, on the fault of the same name to the north and east of the city, is probably the most powerful recorded in New Zealand history. It produced vertical movements of two to three metres over a huge area and turned part of the harbour floor into tidal swamp.

Much of that ground was later reclaimed and is now the financial district. The Old Government Buildings, completed in 1876, were raised precisely on land taken from the harbour. Plaques set into the pavement mark where the shoreline ran in 1840: it is the fastest way to understand the city.

02 The fault draws the city

The Wellington Fault crosses the centre of the city from north to south, and you can see it with the naked eye: the western edge of Lambton Harbour is a straight line, and immediately behind it the ground rises abruptly to the upper suburbs.

It is not alone. Several hundred minor faults have been identified within the urban area, and seismic activity is high even by New Zealand standards. Anyone living in a tall building notices several tremors a year.

The urban result is a city on two very distinct levels: the flat, reclaimed platform holding the offices and the shops, and the wall of hills immediately behind, holding almost everything else.

03 Which is why the city is made of timber

For many years after 1855, the vast majority of Wellington's buildings were built entirely of wood. The logic was simple: timber moves with the ground and masonry does not.

One extraordinary piece survives from that period. The Old Government Buildings, completed in 1876 after twenty-two months of work, hold 143 rooms, 126 fireplaces, 22 chimneys and 804 sash windows, with hardwood framing and kauri weatherboards. It is the largest wooden building in the southern hemisphere.

In housing the habit never changed. The slopes are covered in weatherboard villas with sheet-metal roofs, painted in flat colours, and timber framing is still the usual structural system in almost all residential construction.

04 Nowhere to grow

Wellington is the densest city in New Zealand, and not by planning decision: between the harbour and the hills there is no available ground. The suburbs climbed the slopes and growth was diverted to the Hutt valleys, to the north-east.

Added to that tightness is one early decision. In 1840 the founders set aside a continuous band of land around the settlement on the condition that nothing would ever be built on it: the Town Belt. It began at 625 hectares and now holds about 425, turned into bush, parks and tracks ringing the centre.

The plan is completed to the east by the Miramar Peninsula, joined to the rest by a low flat isthmus at Rongotai. That isthmus, the only decent piece of flat ground left, is where the airport is.

05 How to get around

The centre is walkable end to end. Lambton Quay to Cuba Street is twenty minutes, and the waterfront links the marina, the wharves and the urban beaches of Oriental Bay in a straight line.

To read the city from above there is the Mount Victoria lookout, at 196 metres, and the western hills, reached by a funicular from Lambton Quay. From either one the step of the fault reads with almost textbook clarity.

At 41° 17' south, Wellington is the southernmost capital in the world, a city of a little over 210,000 people — some 414,000 in the functional urban area — that fits inside a day's walking. Its shape was not decided by a plan: it was decided by a fault and an earthquake.