STRANGE TUNNELS

THAMES TUNNEL, LONDON.

This was the first tunnel going under a body of water

and it was the first time the shield tunnelling concept was used.

The tunnelling shield was a device developed by

Sir Marc Isambard Brunel that acts as a temporary

support structure, allowing construction crews to safely

and dryly install permanent support systems underwater.

Building the Thames Tunnel was such a novelty in

the early 19th century that visitors would pay to walk inside

the construction site, and Brunel even hosted concerts

and banquets inside the unfinished structure.

When the tunnel was completed in 1843,

Queen Victoria knighted Brunel for his world-changing

contribution to engineering.

 SEIKAN TUNNEL, HONSHU, JAPAN.

 At 787 feet below sea level, the Seikan Tunnel is the

deepest tunnel in the world.

The region's unpredictable geology and its volcanic rock

prevented engineers from using boring machines,

forcing them to blast and dig their way under the Tsugaru Strait.

 EISENHOWER-JOHNSON MEMORIAL TUNNEL.

There's a lot that makes the Eisenhower Tunnel stand out,

such as its 11,158-foot elevation, which makes it one of the

highest tunnels in the world, as well as the fact that it's the

longest mountain tunnel in the U.S. interstate system.

Adding to the structure's mystique is that it cuts under the

Continental Divide, the point at which bodies of water that drain

into the Pacific are divided from the bodies of water that

drain into the Atlantic.

 LAERDAL TUNNEL, SOGN OG FJORDANE, NORWAY.

Laerdal Tunnel, which stretches under Norway's mountainous

and fjord-filled terrain for 15 miles, making it the longest

completed road tunnel in the world. 

The tunnel is divided into several different sections,

breaking up the drive and creating the impression that

commuters are traveling through a handful of smaller tunnels.

CHANNEL TUNNEL, COQUELLES, FRANCE.

Commonly known as the Chunnel, this structure links England

and France and was completed in 1994.

The advent of modern boring machines and the

indisputable economic benefit of joining the two countries

helped bring the concept to fruition, resulting in one of the

most impressive demonstrations of engineering prowess of all time.

ZION-MOUNT CARMEL TUNNEL, ZION CANYON, UTAH.

This scenic structure is between Utah's Mount Zion National Park

and Bryce Canyon National Park. Construction dates back to

the formative years of the U.S. National Park Service and a

dedication ceremony opened the tunnel to traffic on July 4, 1930. 

A series of windows carved though the tunnel's side

open up breath taking views for drivers.

YERBA BUENA ISLAND TUNNEL,

BAY AREA, CALIFORNIA.

Yerba Buena Island is a small chunk of land resting in the

San Francisco Bay, between Oakland and San Francisco.

A cantilevered bridge flanks this five-lane tunnel on one side,

with a double suspension bridge on the other. 

With a 76-foot diameter, Yerba Buena Island Tunnel is the

world's widest single-bore tunnel, an impressive feat considering

it opened in November of 1936. 

INFILTRATION TUNNELS, 38TH PARALLEL DMZ 

Three different tunnels were discovered creeping under

Korea's Demilitarized Zone, one of the most contentious

borders in the world, throughout the 1970s. All of them

appeared to originate in North Korea, and later, in 1990,

a fourth tunnel was discovered. 

The Third Invasion Tunnel, also referred to as the

Third Tunnel of Aggression, came within 26 miles of Seoul,

 South Korea's capital city. Clandestine, underground

routes provide North Korea the means to launch a massive

military offensive, and, as the tunnels were large enough to

shuttle through an entire military division per hour.

GlobalSecurity.org estimates that as many as 20 tunnels encroach

on the DMZ; a frightening number given the precarious relationship

between North and South Korea.