Coastal Road: 100 meters of underground tunnel dug in Mumbai
Is the Holland tunnel 46 feet deep and 390 feet wide and 100 miles long? - Quora
How to Build a Tunnel: 14 Steps (with Pictures) - wikiHow
The history of inspired diggers who have taken to making their own tunnels as a hobby.
City of Water | The New Yorker
Before Black Lung, The Hawks Nest Tunnel Disaster Killed Hundreds : NPR
Who owns the space under cities? The attempt to map the earth beneath us | Cities | The Guardian
Record-long drug-smuggling tunnel found from Mexico to San Diego - ABC News
The World's Longest Road Tunnel - Laerdal Tunnel, Norway - Verdict Traffic
The World's Longest Road Tunnel - Laerdal Tunnel, Norway - Verdict Traffic
One Man Spent 38 Years Digging A Tunnel - YouTube
The world's longest railway tunnels - Railway Technology
Holland Tunnel - Wikipedia
Tunnel of Eupalinos - Wikipedia
Swarms of Mini Robots Could Dig the Tunnels of the Future | WIRED
US-Mexico border: 'Longest ever' smuggling tunnel discovered - BBC News
Germany: Robbers dig 100-foot tunnel to raid bank - The San Diego Union-Tribune
The Long Dig | The New Yorker
One Man Spent 38 Years Digging A Tunnel - YouTube
US-Mexico border: 'Longest ever' smuggling tunnel discovered - BBC News
Mysterious shaft dug near archaeological museum in East Jerusalem | The Times of Israel
Brazil Police Foil What Would Be World's Biggest Bank Robbery Ever - brazzil
Lighting effects in the longest road tunnel in the world – the Lærdal Tunnel
