Copenhagan Metro's new M3 Cityring line is a game-changer | CNN Travel
Cityringen M3, Copenhagen metro network | Crestani 2000 srl
Copenhagen Metro's new designer Circle Line | VisitDenmark
M3 Cityringen is Copenhagen Metro's new metro line, which is a 15.5 km underground railway with 17 brand new stations in Copenhagen. (Photo credit: Gonzales Photo - Astrid Maria Rasmussen Stock Photo - Alamy
File:Copenhagen Metro with City Circle Line map.svg - Wikimedia Commons
Copenhagen Metro's new designer Circle Line | VisitDenmark