Those who know where to look will spot a secret hiding in plain sight on the southern slopes of Monte Alpi. It’s hard to find, but an eagle eye will notice the fossil of an enormous fish barely visible against a large, gray stone slab.

The fossil is said to be a member of the Istiophoridae fish family, most likely a Blue Marlin. It’s believed to be about 30 million years old. The nearly eight-foot-long, three-foot-high fish was first noticed in 1982.

Seeing this long-dead fish is an amazing look back in time. It’s fascinating evidence of when this mountain was submerged beneath the sea.

As it's not easy to see the fossil between the rocks, bring some water and pour it over the stone slab. Darkening the rock this way makes the fish slightly easier to find, though it still requires a bit of imagination (a nearby sign also helps you visualize what you should be looking for).

The whole of Monte Alpi itself is interesting, too. Situated near the small town of Latronico, it’s one of the highest mountains of the Lucanian range of the Apennines and is one of the most interesting and untouched areas of the mountain range.