The bridge that has transformed Auckland, the Auckland Harbour Bridge, turns 60 on Thursday.
To celebrate, Vector will be putting on a display with lights on the bridge each night from tomorrow until Monday.
The 3-5 minute show will be repeated at half-hour intervals from 6pm to 10pm.
The bridge was officially opened on May 30, 1959.
The concrete and steel structure was built to a "coat-hanger" design, with a 243m-long span in the middle, to allow ships to pass underneath.
A bridge for the site was first proposed in 1860, but it was considered too expensive for the infant province. Only in the 1940s did the idea gain real momentum.
Hampered by the harbour divide, the North Shore's growth rate was still only half the Auckland average in the mid-1950s. Ferries were the main option for crossing the Waitematā. The alternative, for car owners, was a 50km journey - from Devonport to the Auckland CBD - through Riverhead.
A five-lane bridge with two footpaths was proposed, but this, too, was thought too costly. A slimmed-down four-laner with no footpaths got the tick, at £7.516 million (about $346 million today).
Tolls were charged for crossing the bridge until 1984. At first, car drivers paid 2 shillings and sixpence (25c, worth about $5.75 today).
Four lanes soon proved too few for car-city Auckland and in 1969, the project was completed to add four more via two-lane clip-on bridges, one on each side of the original structure.
In 1990, the moveable lane barrier was installed to prevent head-on crashes and to improve traffic flow at peak times.
The New Zealand Transport Agency says the bridge is monitored through cameras by staff at a traffic operations centre in Takapuna. They assess traffic flow and call emergency services and tow-trucks as needed.
As Auckland's population grows and transport tastes change, the bridge will change and no doubt gain a sibling.
The transport agency is designing an add-on path for pedestrians and cyclists. Construction is expected to start next year.
And following years of reports into a possible new bridge over - or tunnel under - the harbour from central Auckland to the North Shore, the Transport Agency and Auckland Council say they expect to report on their latest "harbour connections" investigations by mid-year.