Nangkartshang Peak is one of the classic "trekking peaks" in the Khumbu. It is accessible from either Pheriche or Dingboche, though I will suggest the standard route from Dingboche (as is reflected in the GPX file), as this seems like the more obvious, aesthetic choice.

The route can either be completely snowed over or completely dry, depending on the weather and time of year. Your author has climbed it in both conditions (snow in March and clean in late October).

Scenic Marathon route along the Alpstein mountains. Starting in Wasserauen, go on to Schaefler, Säntis, Lysengrat, pass the Altmann ridge and then along Saxer Lücke to Hoher Kasten. 

The route described below is one of several routes in Olympus (Greece) that are somewhere at the intersection of running, hiking and rock climbing, so all of these skills are needed.