Started after World War II to compete with the Soviet Union in the space race, DARPA is most famous for fostering the research that led to the creation of ARPANET, the precursor to the internet we use today. At the agency’s small gift store, which is not accessible to the public, one can by replicas of a cocktail napkin on which someone sketched out the rudimentary state of computer networks in 1969.

DARPA later funded the research the gave rise to drones and Apple’s digital assistant, Siri. But it is also responsible for the development of Agent Orange, the potent defoliant used to devastating effect during the Vietnam War.