![Sài Gòn River Tunnel](https://c1.vgtstatic.com/thumb/2/3/237420-v1/sa-i-ga-n-river-tunnel.jpg)
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![Rauhammar Tunnel](https://c1.vgtstatic.com/thumb/1/3/134469-v1/rauhammar-tunnel.jpg)
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![Stokkviknakken Tunnel](https://c1.vgtstatic.com/thumb/1/3/134495-v1/stokkviknakken-tunnel.jpg)
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![Churia Tunnel](https://c1.vgtstatic.com/thumb/2/3/232643-v1/churia-tunnel.jpg)
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![Sjønståfjell Tunnel](https://c1.vgtstatic.com/thumb/1/3/134494-v1/sj-nst-fjell-tunnel.jpg)
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![Small tunnel](https://c1.vgtstatic.com/thumb/1/3/134231-v1/small-tunnel.jpg)
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![Håggå Tunnel](https://c1.vgtstatic.com/thumb/1/3/134634-v1/h-gg-tunnel.jpg)
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![Northland Tunnel](https://c1.vgtstatic.com/thumb/1/3/134233-v1/northland-tunnel.jpg)
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![Đường Hầm Hỏa Xa](https://c1.vgtstatic.com/thumb/2/3/238147-v1/a-a-a-ng-ha-m-ha-a-xa.jpg)
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![Helensburgh Glow Worm Tunnel](https://c1.vgtstatic.com/thumb/2/5/254745-v1/helensburgh-glow-worm-tunnel.jpg)
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![Great Siege Tunnels](https://c1.vgtstatic.com/thumb/2/4/247528-v1/great-siege-tunnels.jpg)
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![Harecastle Canal Tunnel](https://c1.vgtstatic.com/thumb/2/4/249215-v1/hardcastle-canal-tunnel.jpg)
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![Union Canal Tunnel](https://c1.vgtstatic.com/thumb/2/3/236139-v1/union-canal-tunnel.jpg)
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![Emilia tunnel](https://c1.vgtstatic.com/thumb/2/4/246031-v1/emilia-tunnel.jpg)
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![Ptarmigan Tunnel](https://c1.vgtstatic.com/thumb/2/5/252295-v1/ptarmigan-tunnel.jpg)
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![Szklary railway tunnel](https://c1.vgtstatic.com/thumb/2/4/241263-v1/szklary-railway-tunnel.jpg)
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![Hualien train derailment (4/2/21)](https://c1.vgtstatic.com/thumb/2/4/241319-v1/hualien-train-derailment-4-2-21.jpg)
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![Da Lat Clay Tunnel](https://c1.vgtstatic.com/thumb/2/4/249460-v1/da-lat-clay-tunnel.jpg)
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![Almkanal of Salzburg](https://c1.vgtstatic.com/thumb/2/5/251001-v1/almkanal-of-salzburg.jpg)
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![Edgbaston Canal Tunnel](https://c1.vgtstatic.com/thumb/2/4/249213-v1/edgbaston-canal-tunnel.jpg)
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![Leek Tunnel](https://c1.vgtstatic.com/thumb/2/4/243561-v1/leek-tunnel.jpg)
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![Upton Chamber](https://c1.vgtstatic.com/thumb/2/5/250743-v1/upton-chamber.jpg)
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![Sarajevo Tunnel](https://c1.vgtstatic.com/thumb/2/5/252554-v1/sarajevo-tunnel.jpg)
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![Snarestone Tunnel](https://c1.vgtstatic.com/thumb/2/5/251073-v1/snarestone-tunnel.jpg)
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![Permafrost Tunnel Research Facility](https://c1.vgtstatic.com/thumb/2/4/248784-v1/permafrost-tunnel-research-facility.jpg)
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