Venice calls itself the Shark Tooth Capital of the World, and it earns it: black fossil shark teeth wash out of the old sea floor and onto the beach by the thousand, and you sift the shallow surf with a wire scoop for them. Most are small, but the ones everybody wants are the palm-sized teeth of the megalodon, the giant shark. Free to hunt on the public beach; a scoop and patience are all it takes.
Fossil shark teeth & megalodon
See it on the map
Other places on the map within a couple of hours.