JUNE 2012 Engadin St. Moritz - UNESCO World Heritage site. The UNESCO World Heritage recognition of the high-altitude engineering won- derland through Switzerland’s Engadin Valley honors one of the most spectacu- lar, technically innovative and harmonious narrow-gauge railways. Since the exten- sion of the road system through these passes, the construction of the Rhaetian UNESCO World Heritage Site, Rhaetian Railway