The pumphouse controls water from the Dee which serves Llangollen Canal
The stone building on the banks of Llangollen Canal's imposing source, the Horseshoe Falls, may appear unremarkable - but looks can be deceptive.
Now, for only the second time in its 60-year history, the valve house which regulates water into the canal via an intricate system, is opening to the public.
The event, which includes a talk and an exhibition of old photos, is to promote local heritage as the canal was made a World Heritage Site last year.
Thomas Telford built Horseshoe Falls to serve Pontcysyllte Aqueduct
And even though the canal's water source, the Dee, is visited by thousands of people annually, the valve house interior has remained a mystery until its trial open day earlier this month.
Under its remit to promote the World Heritage Site which features the first 11-mile (17k) stretch of the canal from its source, Pontcysyllte & Llangollen Canal Project is hosting a series of walks, talks, heritage visits and conferences.
Community project officer Piers Warburton said: "Experts will be on hand to explain the workings of the valve house and why it is still as important today as it was 60 years ago.
"With the help of local people, we have also put together a display of historical photographs showing the surrounding area in the 1930s."
Built in 1947, the centrepiece of the valve house is a 20ft long 3ft diameter pipe running 8ft below ground level, connecting the River Dee water source with Llangollen Canal.
The water flow is controlled by guillotines which, in turn, are raised and lowered by levers within the building.
The Horseshoe Falls was constructed 200 years ago by Thomas Telford to maintain water levels in the Llangollen Canal and across Pontcysyllte Aqueduct.
The valve house opens on Saturday, 29 May, between 10am and 12.30pm