Namche Bazaar (3,440m) is the capital of the Khumbu — the main market town, the main acclimatisation stop, and the hub through which nearly all Everest-region traffic passes. The town is built in a natural amphitheatre on a steep hillside, its stone-and-plaster buildings stepping up in tiers around a central horseshoe of teahouses, gear shops, bakeries, and internet cafes. The setting is dramatic and the facilities surprisingly good: you can get an espresso in Namche, watch a movie, buy new gear, and transfer money.
Most trekkers spend two nights here for acclimatisation, and the acclimatisation day walk above town to the Everest View Hotel and the ridgeline overlook is superb — Ama Dablam, Everest, Lhotse, Nuptse, and Thamserku all visible from the same vantage point. The Sherpa Cultural Museum at the top of town has an excellent collection of tools, clothing, and photographs documenting the history of Khumbu before expeditions. The Saturday market at the base of town is genuinely local: yak cheese, fresh vegetables brought up by porter, and Tibetan goods from across the border.
From Namche, trails branch to Khumjung, Thame, Tengboche, and Gokyo. The whole of the Khumbu is accessible from this base.