A television crew descended on a quarry to film scenes for a popular soap.
Cameras were recording at Eccleston Delph on Wednesday.
It is thought they were filming for an exciting upcoming storyline in Channel 4 soap Hollyoaks, due to be broadcast in the autumn.
Lime Pictures, which makes Hollyoaks, and Eccleston Delph Water Sports Centre both remained tight-lipped about the filming when contacted by the Guardian, to avoid storylines being revealed.
But it is not the first time Eccleston Delph has been used as a location for Hollyoaks.
Fans may recognise it as the place where a car plunged into water when character Clare Cunningham tried to kill her husband Max in 2007.
The Delph, which ceased to be an active quarry in 1953, also hit the headlines in October 1979 when amateur divers found a handless body badly mutilated to prevent its identification.
The body was that of New Zealand drugs baron Marty Johnstone and its discovery led to a worldwide investigation.
It resulted in members of the so-called Handless Corpse gang being jailed for their parts in the murder and drugs case.
The quarry, on Halfpenny Lane, Eccleston, was redeveloped into a scuba diving centre more than 10 years ago.
It was previously filled with sludgy water and abandoned cars, but became one of the most popular open water swimming venues in the region.
It now includes underwater attractions and wrecks, training platforms and is stocked with a variety of fish.