No one expected archaeologist William Kelso to find the "lost" English fort built at Jamestown, Virginia in 1607, but he did. Now the 70-year-old expert hopes to follow the evolution of the fort with the help of university students. (video)

The latest project for Kelso is a guardhouse, built in 1608, and expansion of the original fort to its 1617 dimensions. "Our original goal was to find the fort — then trace its evolution through time," Kelso says. "There's so much left to discover here you could keep digging for years."