"Mind your head and watch your step!"
Watch your step in the caves
This warning constantly echoes through the new-look Nottingham caves as visitors explore the musty caverns.
The historic caves have new inhabitants who are keen to show off their work - but they don't want anyone leaving with a sprained ankle or bruised head.
BBC News Online's tour guides for a preview of the revamped caves were Paul Baker and Peter Armstrong.
They claim to have transformed the underground labyrinth from a "dry" tourist attraction into an "exciting experience".
Over the past three weeks, Mr Baker has been project manager for the £50,000 redevelopment.
He says: "People who visit here now can feel like they are stepping back in time.
"Before it was just like you were visiting caves in the 21st century and looking at things... now we are really taking people back and giving them an experience.
"The place is a lot more family friendly."
Mr Baker, on secondment from Nottingham Trent University, bubbles with enthusiasm as he discusses the caves' importance.
"The caves are a scheduled ancient monument, like Stone Henge, which is the most protection you can have in this country.
"Nottingham is littered with caves like this and they all have that protection."
However the special listing poses problems when creating a tourist attraction.
For example, there is a ban on drilling or attaching anything to the stone walls.
Previously known as the Caves of Nottingham, the site has been renamed "City of Caves".
The title was coined by the facility's new lessee, the Galleries of Justice, which is a museum just down the road.
The museum won the lease after the city council terminated its deal with the previous occupiers, Caves of Nottingham Ltd.
Key aspects of the caves' overhaul - which is formally unveiled on Friday - include the installation of sound effects, models, a steaming water well and interpretive signs.
The caves also have three full-time interpreters, who wear costumes and play the parts of an archaeologist, air raid warden and tanner.
Mr Baker is most excited by the new air raid shelter exhibit, which recreates a shelter from World War II.
Little attention has previously been paid to this aspect of the caves' history, he says.
"There are 86 caves that were used as air raid shelters in Nottingham.
"There is such a nostalgic attraction to World War II and I thought it was a shame that wasn't being reflected."
Mr Armstrong is chief executive of the Galleries of Justice, meaning he now oversees the caves as well.
CITY OF CAVES
Nottingham has more man-made caves than any other British city
The area was once known as Tigguo Cobauc (900 AD) meaning 'place of caves'
A tannery operated in the caves from 1500-1640
The whole organisation is controlled by the educational charity Museum of Law Trust Co.
Mr Armstrong explains: "What this means is that any profits made by the caves will be going towards helping young kids at risk."
He is confident a profit will be made and is aiming to increase annual visitor numbers from 52,000 last year to at least 60,000 this year.
Adult admission has been increased from £3.75 to £4, while children and concession entry fees have stayed at £3.
"That is party to cover extra costs, but I don't think 25p will make a difference to people visiting," Mr Armstrong says.
The caves will close again in 15 months to allow for an expansion of the Broadmarsh Shopping Centre above them.
During this closure Mr Armstrong is hopeful extra caves can be made safe, allowing for an expanded City of Caves to be opened to the public when the shopping centre work is finished.