The Mattmarksee is a reservoir built in the early 1960's between the Rimpfischhorn and Stellihorn mountains in the Swiss Alps.
iss061e004462 (Oct. 8, 2019) — The Mattmarksee, a reservoir built in the early 1960’s between the Rimpfischhorn and Stellihorn mountains in the Swiss Alps, was photographed from the International Space Station at an altitude of 253 miles above Switzerland.