VOICED : Poland's mighty Vistula turns up gems

The Vistula River in Warsaw has reached its lowest level in two centuries due to a dry summer. This contrasts with past high water levels, such as in 2010. The low levels have uncovered historical artifacts, including ruins of a WWII bridge and a wooden riverboat. Archaeologists are taking advantage of these discoveries before the river rises again.

What was the condition of the Vistula River in the spring of 2010?

What challenges do archaeologists face as they explore the riverbed?