Hot air balloons, or lighter-than-air craft, have been around for centuries. But it wasn't until March 1999 that humans were able to circumnavigate the entire world in a single hot air balloon flight. 

The two guys who did it were British balloonist Brian Jones and Bertrand Piccard, a Swiss psychiatrist and balloonist. 

They co-piloted a massive balloon called Breitling Orbiter 3,  which launched March 1st,1999 from Switzerland and landed in Egypt 19 days and 27-thousand-900 miles laer.