These sealed crates could hold nearly anything. (credit: Tomasz Stachura/ Baltictech/Handout via REUTERS )

A World War II shipwreck recently located off the coast of Poland may hold the dismantled pieces of the Amber Room, a Russian treasure looted by the Nazis and lost since 1945.

The wreck of the German steamship Karlsruhe lies 88 meters (290 feet) below the surface of the Baltic Sea and a few dozen kilometers north of the resort town of Ustka, Poland. It’s in excellent shape after 75 years on the bottom, according to the team of 10 divers from Baltictech who located the wreck in June and announced the find in early October.

“It is practically intact,” Baltictech diver Tomasz Stachura told the press in a statement.

(credit: Uryadovy Courier )

Coal miners in Serbia recently dug up an unexpected surprise: three probable Roman-era ships, buried in the mud of an ancient riverbed for at least 1,300 years. The largest is a flat-bottomed river vessel 15 meters (49 feet) long, which seems to have been built with Roman techniques. Two smaller boats, each carved out from a single tree trunk, match ancient descriptions of dugout boats used by Slavic groups to row across the Danube River and attack the Roman frontier.

The Kostolac surface mine lies near the ancient Roman city of Viminacium, once a provincial capital and the base for a squadron of Roman warships on the Danube River. When the Roman Empire ruled most of Southern Europe, the Danube or one of its larger branches flowed across the land now occupied by the mine. The three ships lay atop a 15-meter- (49-foot-) deep layer of gravel, buried under seven meters (23 feet) of silt and clay, which preserved them for centuries in remarkably good condition—or did until the miners' earthmoving equipment dug into the steep slope to excavate for the mine.

"The [largest] ship was seriously damaged by the mining equipment," archaeologist Miomir Korac, director of the Archaeological Institute and head of the Viminacium Science Project, told Ars in an email. "Approximately 35 percent to 40 percent of the ship was damaged. But the archaeological team collected all the parts, and we should be able to reconstruct it almost in full." With any luck, that reconstruction will help archaeologists understand when the three ships were built and how they came to rest in the riverbed.

Enlarge / These curved timbers, called knees, help support deck beams. (credit: Jim Hansson, Vrak Museum of Wrecks )

Two 17th-century shipwrecks on the bottom of a busy Swedish shipping channel may be the sister ships of the ill-fated Vasa . Archaeologists with Sweden's Vrak—Museum of Wrecks discovered the vessels in a 35-meter-deep channel near Stockholm during a recent survey. Neither wreck is as well-preserved as Vasa (to be fair, there are probably ships actually sailing today that aren't as well-preserved as Vasa ), but they're in remarkably good shape for several centuries on the bottom.

Studying the wrecks could reveal more details about how early naval engineers revised their designs to avoid another disaster like Vasa .

Hiding in plain sight

The wrecks may be the remains of two of the four large warships Sweden's King Gustav II Adolf built in the 1620s and 1630s. The earliest of the four ships, Vasa , had a first trip out of port in 1628 that ended in disaster; the top-heavy vessel caught a gust of wind and leaned over far enough to let water rush in through open gun ports. King Gustav's prized warship sank just a few dozen meters offshore in front of hundreds of spectators.