A trove is a valuable collection of something. You might discover a trove of old comic books in the basement of your uncle's house, or a trove of candy bars at the back of a kitchen cabinet.
If you found a treasure chest full of gold doubloons buried in your back yard, you could absolutely call that a trove — but you can also use trove for any wonderful or precious stash of stuff. Archaeologists might uncover a trove of fossils, and Easter egg hunters are hoping to discover a trove of eggs and candy. Trove was first used in the phrase treasure trove, from the Anglo-French tresor trové, rooted in the Old French trover, "to find."