From the Jungfraujoch station, take the 100-meter elevator to the top of the Sphinx observation deck, among the tallest observatories in the world. You can see the Jungfrau, Mönch, and Eiger peaks from the observation deck, as well as the whole Aletsch Glacier. The Sphinx observatory is among the tallest observatories in the world, with a telescope, a meteorological station, and two sizable laboratories (although this isn't accessible to the public).