Everest base camp tents are visible below Khumbutse (6639 meters), March 15, 2013. These penitentes were not entirely free standing like the ones in the Chilean Andes.
According to Wikipedia, Penitentes "are a snow formation found at high altitudes. They take the form of tall thin blades of hardened snow or ice closely spaced with the blades oriented towards the general direction of the sun. Penitentes can be as tall as a person."