On either side of the Demilitarized Zone (DMZ), the approximately 150-mile-long, 2.4-mile-wide strip separating North Korea and South Korea, lie armies, weapons and other markers of war.
At the observation post in Paju, a city situated just south of the world-watched 38th parallel, a South Korean solider stands. South Korea and its volatile neighbor have never officially ended the Korean War, signing an armistice that created the DMZ in 1953.
South Korea has assembled an army of about 495,000 troops. Here, a group of its soldiers performs a demonstration of a search operation near the DMZ.
Ready for fire
The K200, pictured, is a Korean Infantry Fighting Vehicle. It's one of about 2,700 armored vehicles at the disposal of the South Korean army.
The FA-50 fighter jet, seen here at the South Korean air base in Cheongju, joined the ranks of the South Korean air force in 2013.
The South Korean army's M48A2 tank, pictured, is a diesel-powered variant of the United States-designed M48 Patton battle tank.
Watching the sky
Mobile surface-to-air Patriot missile defense systems are one of South Korea's major weapons systems. A Patriot Advanced Capability-2 missile launcher is seen here in 2017. The South Korean military is reportedly looking to upgrade to the PAC-3.
The 14,000-ton Dokdo is the largest ship in the South Korean navy. According to the Korea Times, it can transport up to 720 marines, six tanks, seven amphibious assault vehicles, 10 trucks and seven helicopters.
Loudspeakers trained to the north are another relatively low-tech tool in South Korea's arsenal. The south uses the speakers to broadcast loud weather forecasts.
Enter the marines
South Korea's marine corps has about 28,800 troops. Here, marines from the country's 2nd Marine Division roll out during a 2016 demonstration at a base in the city of Gimpo near the DMZ.
Following a North Korean nuclear test in 2017, the South Korean military released this photo of a Hyunmoo-2 ballistic missile.
Show of force
In 2017, these F-15K South Korean fighter jets dropped 2,000-pound MK 84 bombs at the Taebaek Pilsung Firing Range in a show of force.
On a roll
The South Korean army features approximately 2,400 tanks, including this K1 main battle tank, seen here firing smoke shells during a 2011 drill in Paju.
The K2 main battle tank is pictured during a live-fire drill in 2015.
Amphibious assault vehicles used by South Korea's marine corps kick up dirt during a demonstration in Gimpo.
The KA-1 aerial control-attack aircraft, seen at the United States' Osan Air Base in Pyeongtaek, has been part of South Korean air-defense force since 2007.
The South Korean Air Force boasts 65,000 troops and 400 combat aircraft, including this RF-16. It's seen firing flares during a 2017 presentation for the media.
The homegrown T-50 is used by South Korea to train pilots for the F-15 and other fighters.
Lighting up the sky
This Lynx multi-purpose helicopter, seen firing flares in 2017, is one of about 50 choppers deployed by South Korea's 70,000-troop-strong navy.
In 2010, months after a South Korean warship was sunk by a suspected North Korean torpedo attack, the South Korean naval destroyer Choi Young ran drills in the West Sea.
Breaking the surface
The Type 209-class submarine is seen in 2008. It's one of about approximately 10 subs in use by the South Korean navy, per a 2015 report by South Korea's Ministry of National Defense.
Commandos of South Korea's Navy Special Warfare Flotilla, alternately known as the UDT/SEAL team, train in waters off Donghae in 2009.
Hands across the water
In 2013, a joint military exercise by the South Korean and U.S. armies involved a river crossing near the DMZ.
Sunrise at the DMZ
Barbed-wire fencing is low tech, but along portions of South Korea's DMZ border, it's a ubiquitous defense feature.
All paws on deck
Trained sniffer dogs, including this canine seen returning from a patrol in 2010, are part of the South Korean army's effort to police its side of the DMZ border.
So close, so far apart
In the DMZ's Joint Security Area, where the demarcation line separates North from South, a North Korean soldier, rear, comes face to face with his South Korean and United Nations counterparts.