Rui La is 4,998m and stands on the border between Tibet and Nepal. For those on the Manaslu Trek taking a rest day in Samdo, this is a great day trip which aids acclimatisation.
It is a well worn route and now the most commonly used route to Tibet. It takes about five hours walking to reach from Samdo. To get there you have to head north from Samdo following the Athahra Saya Khola (1800 river) until it heads west, then the trails heads eastwards and upwards. Photos and trek details can be found on Guy Shachar’s website. He’s also write up many more Manaslu trek side trips here.
The mountain in the picture above is expedition peak Panbari. It has only been climbed once, and Alpinist.com reported thus:
A Japanese expedition has made the first ascent of Panbari Himal, a remotely situated -meter snow peak in the Nepal’s Peri Himal, very close to the Tibetan border north of Manaslu. The mountain, which was only officially opened to climbers in 2002 and has received no previous attempt, lies immediately north of the 5135-meter Larkya La, a relatively spectacular pass that forms the high point on the increasingly popular Manaslu Circuit. This whole area was closed to foreigners for many years due to its proximity with Tibet, but it was surreptitiously opened in 1991 and it took several years before trekkers caught on.
In front of it, you can see Hindu Himal, Lilya and Athahra Saya Khola Himal and climbing details can be found here.