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

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

https://twitter.com/NatGeoTravel/status/1085808972165042176