Specialist archaeological divers have failed to uncover any treasures during a survey of a water tank in Kent.
Amateur divers had investigated the waters in the early 1990s
They examined a giant cistern underneath a paved courtyard at Knole, a National Trust property in Sevenoaks, on Tuesday.
The owners said the survey had enabled them to see how the underground network of tunnels and arches was constructed.
Knole was built in 1456 and was used as a hunting home by Henry VIII during the 16th Century.
In 2003, part of Stone Court started sinking so a structural radar survey was carried out.
It revealed that the cistern resembled a huge underwater church-like building more than 30ft long, with interlinking tunnels and arches built of carved stone.
The water is 12ft deep and used to be the main source for the house.
Before the divers went in on Tuesday a remote video camera was used to record footage of the structure.
Knole was built in 1456 by the then Archbishop of Canterbury
Afterwards, property manager Steven Dedman said: "We haven't found any crowns or jewels which is a shame I suppose.
"But we have found such a lot of really interesting and useful information for us as the keepers of this property.
"This is just water storage 4m below the ground, never to be seen by anyone, and yet you've got these beautifully carved arches and wonderful brickwork.
"It's just so special to have that and to be able to see it now after 500 years."
The dive allowed the property's owners to see if the structure's current condition would support their planned re-paving of Stone Court.