Bath's most valuable chandeliers get a spring clean at The Assembly Rooms
For 250 years the chandeliers of The Bath Assembly Rooms have been the centre piece of the building. They are so unique there's nothing else like them in the world and so valuable you can't even put a price on them.
But every six months experts are called in to give them a spring clean to preserve them.
"You have to work more slowly and carefully and deliberately", chandelier conservator Juliet Brotheridge told ITV News.
"You can feel a little bit nervous doing this because it is a responsibility and they are incredibly valuable and rare and precious as well as being stunningly beautiful", she added.
These chandeliers were made for the building in 1771 when people came to The Bath Assembly Rooms to dance, gamble and drink tea.
During the Second World War the chandeliers were removed and rumoured to have been hidden in nearby mines for safety. And thankfully they were, as in 1942 Bath was heavily bombed and the Assembly Rooms ceiling was destroyed.
Today the cleaning and meticulous checks of these chandeliers is essential work.
Becky Davies, Project Conservator from The National Trust, said: "Every six months they're lowered, they're checked, their bulbs are changed.
"They are in incredibly good condition because they have always been so well looked after. These chandeliers are considered internationally significant."
The chandeliers were originally lit by candles but over the years have been upgraded to gas, electricity and now have LED bulbs, which comes as a relief to the chandelier conservators.
Terry Brotheridge said: "When it used to be the halogen lights I'd sometimes reach in to clean and it would be so hot I'd get burnt. I've still got burn marks on my arm."
He added: "They're the finest suite of chandeliers in the world there's nothing like them. We invented lead crystal, so it led the way and this building started the fashion of having chandeliers."Visitors will be able to see the cleaning and the lowered chandeliers until the end of the week, when they will all be raised back to the ceiling.