ARI SHAPIRO, HOST:
Severe drought has dried up waterways around the world this year. And as water levels lower, rare glimpses into the past have emerged. German warships sunk in World War II are rising from the Danube. In China, 600-year-old Buddhist statues were discovered in the Yangtze River.
MARY LOUISE KELLY, HOST:
And the Tiber River revealed ruins of a Roman bridge from the first century.
NICHOLAS TEMPLE: The Pons Neronianus, which at the time was the only bridge crossing at that part of the Tiber, may have been the bridge that Saint Peter himself had crossed to his martyrdom.
KELLY: That is Nicholas Temple, senior professor of architectural history at London Metropolitan University. He says the bridge could have been a significant crossing point for Roman armies and pilgrims, and he thinks this is a great opportunity to learn more about it.
TEMPLE: There are parts of the bridge which were not visible in the past - because the drought is so severe and has disclosed lots of things about the substructure and certainly about the early history of the bridge.
SHAPIRO: And in Spain, a prehistoric burial site is now fully visible. Some are calling it the Spanish Stonehenge. All that's left is a circle of tall stones, but at one time it was a grand dome. Angel Castano is president of a local cultural association.
ANGEL CASTANO: You can picture this as a big, huge igloo. The entrance, this kind of little tunnel door, was 12 meters long.
SHAPIRO: Castano thinks the site may have been more than just a communal tomb.
CASTANO: I would compare it to building a cathedral in the Middle Ages. If you make such a huge effort, are you going to use it just for burial? Probably not.
SHAPIRO: Castano's organization wants to remove the stones from the water to better protect them.
KELLY: Meanwhile, in Glen Rose, Texas, traces of life have just been revealed from way farther back - like, 113 million years back. Jeff Davis is superintendent at Dinosaur Valley State Park. There, tracks from the T.rex-like Acrocanthosaurus were left behind by the parched Paluxy River.
JEFF DAVIS: Those tracks have three large toes. Think about a dinner plate, and then add three or four inches on some of them.
KELLY: They roamed the region when it would have been covered by sticky mud and then floodwater.
DAVIS: Layers of sediment were laid on top of them more and more over millions of years. And then in the last few thousand years, the Paluxy River has carved back down through those layers and exposed the tracks.
SHAPIRO: The drought may have brought new discoveries, but it has also brought disaster worldwide. One of the year's largest wildfires in Texas burned within a quarter mile of the park.
DAVIS: A lot of the places in the park, it looks like fall because the trees are so yellow.
SHAPIRO: The low waters that made the prehistoric burial site in Spain visible have meant catastrophe for Spanish farmers.
KELLY: And the reappearance of so-called hunger stones drives home the point. The stones have marked low levels along European rivers during historic droughts. One in the Czech Republic simply reads, if you see me, then weep. Architectural history professor Nicholas Temple again on the stones.
TEMPLE: They got the marks saying this is the minimum level, and it's well beneath the minimum level. We had measures, ways in which we can articulate these changes, but with these measures now gone off the scale.
KELLY: Once the rains come, it'll be a welcome relief, but it will also mean saying goodbye to these finds until the next drought. It's NPR News. Transcript provided by NPR, Copyright NPR.