Any doubt with Oval Office pics always check Getty, they upload many shots
for Tunnel warfare diggers
found a good PDF about North Korean Tunnels
the rest is about other NK tunnels and links to tunnels in other countries
Secret Tunnel Under Panmunjom (PDF) (Report). Korean Overseas Information Service. October 1978.
https://web.archive.org/web/20160304084820/http://www.imjinscout.com/images/North_Korean_Tunnels.pdf
Third Tunnel of Aggression
From Wikipedia, the free encyclopedia
The Third Tunnel of Aggression (Korean: ě ś3ë•…ęµ´) (Third Infiltration Tunnel or 3rd Tunnel) is one of four known tunnels under the border between North Korea and South Korea, extending south of Panmunjom.
https://en.wikipedia.org/wiki/Third_Tunnel_of_Aggression
Incursion tunnels
See also: Tunnel warfare
Since 15 November 1974, South Korea has discovered four tunnels crossing the DMZ that had been dug by North Korea. The orientation of the blasting lines within each tunnel indicated they were dug by North Korea. North Korea claimed that the tunnels were for coal mining; however, no coal was found in the tunnels, which were dug through granite. Some of the tunnel walls were painted black to give the appearance of anthracite.[25
The tunnels are believed to have been planned as a military invasion route by North Korea. They run in a north–south direction and do not have branches. Following each discovery, engineering within the tunnels has become progressively more advanced. For example, the third tunnel sloped slightly upwards as it progressed southward, to prevent water stagnation. Today, visitors from the south may visit the second, third and fourth tunnels through guided tours.[26]
First tunnel
The first of the tunnels was discovered on 20 November 1974, by a South Korean Army patrol, noticing steam rising from the ground. The initial discovery was met with automatic fire from North Korean soldiers. Five days later, during a subsequent exploration of this tunnel, US Navy Commander Robert M. Ballinger and ROK Marine Corps Major Kim Hah-chul were killed in the tunnel by a North Korean explosive device. The blast also wounded five Americans and one South Korean from the United Nations Command.
The tunnel, which was about 0.9 by 1.2 m (3 by 4 ft), extended more than 1 km (1,100 yd) beyond the MDL into South Korea. The tunnel was reinforced with concrete slabs and had electric power and lighting. There were weapon storage and sleeping areas. A narrow-gauge railway with carts had also been installed. Estimates based on the tunnel's size suggest it would have allowed considerable numbers of soldiers to pass through it.[27]
Second tunnel
Entrance to the North Korean-dug 4th Infiltration Tunnel, Korean DMZ
The second tunnel was discovered on 19 March 1975. It is of similar length to the first tunnel. It is located between 50 and 160 m (160 and 520 ft) below ground, but is larger than the first, approximately 2 by 2 m (7 by 7 feet).
Third tunnel
Main article: Third Tunnel of Aggression
The third tunnel was discovered on 17 October 1978. Unlike the previous two, the third tunnel was discovered following a tip from a North Korean defector. This tunnel is about 1,600 m (5,200 ft) long and about 73 m (240 ft) below ground.[28] Foreign visitors touring the South Korean DMZ may view inside this tunnel using a sloped access shaft.
Fourth tunnel
A fourth tunnel was discovered on 3 March 1990, north of Haean town in the former Punchbowl battlefield. The tunnel's dimensions are 2 by 2 m (7 by 7 feet), and it is 145 metres (476 ft) deep. The method of construction is almost identical in structure to the second and the third tunnels.[29]
https://en.wikipedia.org/wiki/Korean_Demilitarized_Zone#Incursion_tunnels
https://en.wikipedia.org/wiki/Subterranea_(geography)
https://en.wikipedia.org/wiki/Category:Tunnels_by_country
https://en.wikipedia.org/wiki/Category:Tunnels_in_Asia_by_country
https://en.wikipedia.org/wiki/Category:Tunnels_in_China