The Dunedin Gasworks Museum is one of only three known preserved gasworks museums in the world.
On Saturday, the museum opened its doors for free to the public to turn back the clock and take part in celebrating 160 years since New Zealand's first and last gasworks was opened.
Dunedin Gasworks Museum Trust chairman Jonathan Cweorth said the open day gala was to celebrate an incredible milestone.
"It’s really rare worldwide to have a gasworks that’s open and still functioning, so it’s a real heritage gem in Dunedin and being able to celebrate 160 years is just amazing.
"We’re really excited to be open to the community and welcoming people to the gasworks who may not have been here before."
About 30 people dressed up in their best tweed and took their vintage bicycles for a leisurely spin through Dunedin.
Starting at the Leith foot bridge in Magnet St, tweed enthusiasts cycled for 9.5km to the gasworks museum for the gala.
Tweed Ride organiser Peter Petchey said people rode a mixture of modern and vintage bicycles to take part in the ride.
"It’s an event that’s held worldwide and it's really just a chance to ride a bike and wear your finest tweed."
The museum’s open day gala also included the debut of the Gasworks Growers and Craft market as well as operating steam engines and blacksmith demonstrations.
It was a part of the Southern Heritage Trust Otepoti Dunedin Heritage Festival that will be taking place until October 29.
