hoard
a large amount of sth precious that is hidden or carefully guarded for preservation, future use, etc.
Link to present incidents:
A hoard of more than 52,500 Roman coins discovered in a Somerset field has been declared treasure. Dave Crisp, from Wiltshire, found the coins - dating from the 3rd Century AD - buried in a field, near Frome. (BBC, July 22,2010)