Amazon.com: dspitwod Train Tunnel Building Toy for Classic Electric City Passenger Express Train Tracks Toys Accessories Railroad Construction Building Block Compatible with Major Brand (Train Tunnel) : Toys & Games
City Train Track Tunnel Exit Entrance for Lego Kit Building Blocks Brick Set MOC | eBay
LEGO City Train Archives - GJBricks LEGO Blog
Lego train tunnel | Beau Smith | Flickr
LEGO Train Tunnel Idea - Suggestions and support - LEGO Train Tech - Eurobricks Forums