Inside a block of sandstone is a map to discover a tribe. When the tribe is found, a digging tool reveals a skeleton treasure hunter, their weapon, and a mystery treasure. While most of the treasures are plastic, a heavy draw of the series is the chance for the treasure to be dipped in real gold.
Series 2 introduced the Mini Beasts to the line, small skeletal animals that resemble the treasure hunters. Series 3 would later introduce the Aliens subline. Instead of cutting through sandstone, it’s a slimy alien worm, with a peridot instead of gold at stake.