The United States has by far the strongest military in the world, with the responsibility to maintain the defense of America and its allies and provide peacekeeping forces all over the world. To do this, the United States has established more than 400 military bases on every continent except Antarctica.

These facilities are used for training and deploying troops, for maintaining and testing weapons systems, for research and education, and for aircraft testing. Given the space requirements of these exercises, the physical size of these installations can be considerable.

24/7 Wall Street has compiled a list of America’s 50 largest military bases overseas. The facilities are listed in order of physical size, according to data from the Department of Defense’s Base Structure Report for fiscal year 2017.

Click here to see America’s largest military bases.

Maintaining these facilities is expensive. Congress approved in July 2018 $717 billion in military spending for fiscal 2019, equal to 3.1% of gross domestic product. Though much of the funding goes to paying military service men and women, the bill covers the development of weapons systems, strategic defense technology, and maintaining base operations.

Of the 50 installations on the list, 18 are in Japan and many of those are on the island of Okinawa, a legacy of the intense fighting there during World War II — the costliest war in U.S. history. Eight bases are in South Korea as the United States and South Korea partnered to defend against an attack from communist North Korea following the Korean War. A ceasefire signed in 1953 remains in effect, though the Demilitarized Zone is still one of the tensest borders in the world. Bases throughout Asia have been consolidating in recent decades, resulting in closures of some installations, such as Camp Red Cloud in South Korea this past October.

Some of these bases were taken over by the American military following conflicts and carry the weight of history. The Misawa Air Base in Japan trained pilots for the attack on Pearl Harbor. Camp Fuji, also in Japan, trained samurai warriors in the 12th century. Ascension Island in the South Atlantic was originally used as a base by the Royal Navy to halt the slave trade.

Many installations are named after servicemen who gave the ultimate sacrifice for their country. While they may not rank among the most decorated war heroes in U.S. history, the men many of these are named after were awarded the Medal of Honor, the most prestigious U.S. military decoration.

To create a list of the nation’s largest military bases overseas, 24/7 Wall Street used data compiled by the Department of Defense’s Base Structure Report for fiscal year 2017. The report includes the physical size of military installations in acres, the total financial cost to replace the base, noted as the base value, and the nearest city to the base. Personnel counts data were obtained from the 2016 Demographics Report, compiled by Defense Department contractor Military OneSource. Additional information was gathered from sources such as militarybases.com, virtualglobetrotting.com, military branch websites, and the military newspaper Stars and Stripes.