Homeowners who believe their attics, sheds and garages are full of junk could be sitting on a goldmine, according to a city auctioneer.
This week a battered Rolex watch, found in a box of unwanted items, sold for more than £5,000.
And in a separate auction, an Italian snuff box, discovered in similar circumstances, sold for £4,000 in Lincoln.
John Leatt, of Golding Young & Mawer, and who oversaw its sale, said valuable items can be discovered in the most surprising places.
He said: "I found the snuff box in a box of quite unrelated things that were in the process of being sorted for ordinary sale, so it was completely unexpected.
"It shows you never know what you might find.
"It's not that common that you would have a £4,000 box in your cupboard, but it may be that your grandfather or father collected things, like books, stamps or cigarette cards, that are now quite valuable.
"It's quite an exciting moment when you find something that was completely unexpected."
The snuff box, made with a coveted micro-mosaic panel, was sold on January 23.
It was part of an estate sold by a family whose deceased relative had lived in a village near Lincoln.
After fierce bidding from buyers in America and Europe, an Italian collector walked away with the 19th century antique.
Meanwhile the Rolex, found in Market Rasen, belonged to a widow who was sorting through her husband's belongings.
The 54-year-old Oyster Perpetual GMT Master was covered in scratches, had a broken hand and was faded on the rim.
But the timepiece attracted interest from bidders across the world and was eventually bought by a collector from Berkshire.
It was sold by Scunthorpe-based CJM Auctioneers on January 22.
Paul Cooper, a director at the firm, said: "The lady wasn't stupid and knew it was a Rolex, so thought it would be worth about £1,000.
"But when I rang her to tell her how much it had made I think she thought I was pulling her leg.
"She was absolutely thrilled."
Homeowners who believe they may have found an antique treasure are being encouraged to have it valued.
Mr Leatt said Golding Young & Mawer offer the service for free.
"If you try to sell it on eBay or at a car boot sale you could be making quite a big mistake," he said.
"People have got nothing to lose by bringing things to us to find out what they are really worth."