tunnel network
network of tunnels used for storing or transporting people or material items
Railways in Sydney
overview article
caves of Maastricht
collection of limestone quarries in the Netherlands
Puebla tunnels
System of tunnels under Puebla, Mexico
Hex River Tunnels
railway tunnels in South Africa
Tunnels of Gibraltar
Network of tunnels inside the Rock of Gibraltar, constructed between 1782 and 1968
Marseille Tunnel
succession of tunnels and cut-and-covers in Marseille, France
Disney utilidor system
utility corridor system under Walt Disney World's Magic Kingdom theme park