On Christmas Day last year, Kathryn Bard got an unusual gift.
Working with her colleagues to remove sand from a hillside along Egypt's Red Sea coast, the Boston University archaeologist poked through a small opening that had appeared and felt . . . nothing. She had reached into the entrance to a human-made cave in which sailors stored their gear as many as 4,000 years ago.
Two days later, Bard's team found a larger cave nearby. The same ancient seafarers used this one, she and her colleagues surmised, as a temple or shrine.
These and other discoveries at what was once a port known as Mersa Gawasis offer an unprecedented look at the earliest known sea expeditions conducted for pharaohs. Egyptian archaeologist Abdel Monem Sayed first explored this site 30 years ago, but he didn't report any signs of chambers.
"We know of no other Egyptian ports from this time," Bard says. "Finding these mariners' caves was a big surprise."
In a newly released photograph from the May National Geographic magazine, caver Alan Cressler, shown last August, rappels into Krubera Cave in the Caucasus Mountains of Russiathe world's deepest. Cressler was part of first phase of the Call of the Abyss project. The project's second expedition, in October, became the first to descend more than 2,000 meters (6,560 feet) underground.