People are fascinated with finding things that have sunk in water. The wreck of the R.M.

S. Titanic in the North Atlantic has been a draw since it sank in 1912, but especially since it was found in 1985. In 2023, billionaires died in an experimental craft trying to see it for themselves.

This summer, detailed digital scans of the remains of the “unsinkable” ship were taken in its resting place 12,500 feet below the surface. Just last week, divers explored the long-lost husk of H.M.

S. Hawk off the coast of Scotland, where it was sunk by a German U-boat in 1913. We look at these relics as frozen history.

They might not be preserved in amber, but uncovering these things is a kind of archaeological exploration. They are left in place, the graveyards of the people who died on the ships, ideally reviewed with respect. With a river, there isn’t that clear, otherworldly view that gives a memorial, historical effect.

The metal in a river piles up like, well, trash. When we look at the shimmering surface of the rivers that snake across Pennsylvania, we can focus on the water’s beauty. But a cleanup effort by Living Lands & Waters, an Illinois nonprofit, pulled more than 100,000 pounds of metal out of the Allegheny River in just two days.

There were cars. At least 10 were pulled out with a giant claw. There were car parts.

There was random metal that was hard to identify. Some of it was down there for decades. But this wasn’t left down there to serve as a marker.

“In all the .