U.S. Marines first test against Japanese defenses on Okinawa.

Climb into the guts of a hovercraft, as a team of salvage experts, led by a former NASA engineer, disassemble and cut through this iconic and unique vehicle.

Take a look inside one of the most unusual vehicles ever (2:43)

What's it like to operate a giant hovercraft? There's no better person to ask than a U.S. Navy pilot who has driven the LCAC on tours of duty in Iraq, Afghanistan, and Haiti.

The only way to really understand a hovercraft is to drive one (3:15)

Wales is home to one of the most perfectly-preserved Roman fortifications in all of northern Europe. In Caerwent, near the southern city of Newport, sections of the original first century Roman wall still remain.

Why Wales is the place to see amazing Roman forts (1:49)

The beginning of space exploration was full of questions and unknowns; until they started sending living organisms into orbit, no one knew if the vacuum of outer space would be deadly.

What a sunset on Earth looks like from the moon (2:23)

A group of 49 men and 58 horses upholds a long-standing tradition at Arlington National Cemetery.

The Honorable Tradition in Arlington National Cemetery (1:53)

While the science behind the high bypass ratio engine in a 747 plane may seem complicated, the results are striking. It's capable of delivering over 70 percent more power than a standard engine.

Admiring the power and innovation of a 747 engine (2:46)

Many scientists believe that black holes make sense in the realm of theoretical physics, but couldn't really exist in real life. Capturing an image of a black hole would change all that.

How one picture would prove Black Holes actually exist (3:09)

A team of mechanics are in the process of removing the jet engines from a 747. It's painstaking, careful work—one mistake can lead to irreparable damage to the costly engines.

Removing the engine of a 747 needs expertise and care (3:45)

After years of planning by over 200 international scientists, the data purported to show the first ever image of a black hole is ready. The team gathers for the big reveal—it's a seismic moment in astrophysics.

Scientists reveal first-ever photograph of a Black Hole (3:01)