From pieces of historic bridges and boats to discarded tires and broken glass, Warsaw authorities are exploiting the record low level of the Vistula River to hunt for history and remove trash.

After an unusual wave of heat, the wild-flowing Vistula is at its lowest level since measurements started in late 18th century. In Warsaw, Poland's main river has dropped to some 50 centimeters (20 inches) from the usual average of 200 centimeters, stalling river traffic and exposing treasures and eyesores.

Some 300,000 zlotys (72,000 euros, $79,000) are being spent on retrieving elements of 18th- and early 20th-century bridges and on removing tons of 21st-century waste.

Promoting the clean-up on Wednesday, Warsaw authorities joined cleaners in removing broken bottles, umbrellas and metal pieces from the exposed river bed.