About 800 visitors took the rare opportunity to explore behind the scenes of Tringford Pumping Station on Saturday, March 11.
Built in 1818, the Grade II-listed structure, near Marsworth, has recently undergone a complete restoration by the Canal & River Trust.
Costing £277,000, including a £100,000 award from People’s Postcode Lottery, the restoration work included repairing damaged brickwork, roofing, gutters and windows and improving facilities for volunteers and staff.
Trust experts explained the history and use of the pumping station, which is still in operation almost every day, and keeps the canal topped up with around two million litres of water per year.
Visitors took part in fishing taster sessions and many took the opportunity to do some nature spotting and take a stroll around one of the nearby reservoirs.
Canal & River Trust spokesman Sarah Brown said: “Tringford Pumping Station is the pumping heart of the Grand Union Canal, keeping it topped up with water, but most of its secrets are buried deep underground. Many people don’t realise that without it we wouldn’t keep the Grand Union Canal flowing.
“It was great to celebrate the completion of the repairs with our visitors and demonstrate how we keep the canal topped up. Seeing so many young faces interested in the engineering was great.”
To find out about the Canal & River Trust’s restoration programme and other open days, see canalrivertrust.org.uk/open-days