Historic finds by ordinary people armed with metal detectors were put on display on Thursday.
The leopard cup is said to be one of Wales' highest-quality Roman finds
Amateur enthusiasts stumbled across a decorative Roman "leopard cup" in Abergavenny, Wales, and a Bronze Age weapons cache in Hollingbourne, Kent.
They were among archaeological treasures viewed by Arts Minister Estelle Morris at an event in London.
Many finds would have gone unrecorded if not for a scheme run by the Council for Museums, Archives and Libraries.
Ms Morris was launching the scheme's annual report into more than 49,500 "portable antiquities" found across the country by enthusiasts.
Kent enthusiasts David Button, from Sittingbourne, and Gillian Davies, from Lenham, turned up the first find at Hollingbourne using a metal detector.
'One of our most fabulous finds'
Mr Button alerted the council, who organised an excavation on the site involving many interested locals and the weapons hoard was discovered.
The excavation was described by Ms Morris as a "prime example" of involving local people in archaeology.
Gary Mapps, from Cwmbran, found the Roman cup as he was using his metal detector on farmland near Abergavenny.
A spokesman for the scheme described it as "one of the most fabulous finds recorded with the Portable Antiquities Scheme".
The handle of the cup is a leopard leaning over the rim and was probably imported from Italy in the first century AD.
Some of the exhibits are on show at the British Museum in London.