Worker in a concrete shaft

1280 × 1024

Underground Construction Site — Gray

1200 × 900

Underground Tunnel with Tracks — Gray

1024 × 768

tunnel under construction

3840 × 2400

tunnel construction interior

3840 × 2160

Tunnel construction site

1600 × 1200

Concrete Tunnel Interior — Black, Dramatic, Photograph

1680 × 1050

Concrete Tunnel Interior — Gray, Industrial

2048 × 1280

Concrete Tunnel Interior — Gray, Dull

1920 × 1080

Concrete Tunnel Entrance

2080 × 1544

Excavation in snowy canyon

1200 × 952

Railway Tunnel Interior — Gray, Industrial, Photograph, Tracks

1600 × 1200