Routes across the Alps
photo credits: Nolege, Great St. Bernard Pass, Excerpt von Jens Bunte, CC BY-SA 3.0
Historic Silk Road
photo credits: Jean-Pierre Dalbéra from Paris, France,
Le Registan à Samarcande (Ouzbékistan) (5630435838),
excerpt von Jens Bunte, CC BY 2.0
Isthmus of Panama
photo credits: Madereugeneandrew, Southbound on the Panama Canal approaching the Centennial Bridge, Excerpt by Jens Bunte, CC BY-SA 4.0

