Karsha's Konchod Drubling Nunnery is only a few decades old, but it occupies the site of a far older settlement containing the upper ruins of a fortress, a stupa dating from the 11th century and this small but remarkable temple that's more than a thousand years old. It contains original murals from the time of Ringchen Zangpo and an extraordinary 11-headed statue of the bodhisattva Chenresig in the Alchi style.
To find the key, ask at the nunnery dining room by the central stupa.