Monster Spawners (Dungeons) Don't have a waypoint for /locate

SORRY I PRESSED ENTER AND CREATED AN UNFINSHED BUG REPORT
I want to make the chests in (most) of the dungeons have my own custom loot table, but I'm having trouble finding the dungeons.
I thought you could use /locate to locate a Dungeon, but there isn't a Dungeon locator. This is a half-suggestion, but It's the only generated structure that has loot that you can't use /locate for.