Tunnel profile of the first proposed ship tunnel in the world, Stad Skipstunnel in Vestland, Norway. (image: Wikimedia)

Herrenknecht TBM for Santa Lucia tunnel in Italy between Bologna and Florence. Photo by Herrenknecht press release.

Московские центральные диаметры (МЦД) Moscow Central Diameters graphic: Government of Moscow press office  

Image by Strabag

Vancouver Broadway subway line - image by Acciona press release.

image: VINCI press release

Scheldt Tunnel imagination by Lantis.

Oosterweel link (Oosterweelverbinding) in Antwerp. By WCC.

Austria Semmering Basistunnel (base tunnel) - by Földhegy Wikimedia Commons