This WWI-era invention offers less-seasoned adventurers the opportunity to explore terrain usually reserved for experienced mountaineers. https://on.natgeo.com/2NFAMUi

This WWI-era invention offers less-seasoned adventurers the opportunity to explore terrain usually reserved for experienced mountaineers. https://on.natgeo.com/2NFAMUi 

https://twitter.com/NatGeoTravel/status/1051004635463475200