Phobjikha is a flat-bottomed glacial valley in Bhutan where most of the country's black-necked cranes spend the winter, and the valley put its power lines underground so the birds would not fly into them. About 650 come in off the Tibetan Plateau at the end of October and leave in mid-February. From the viewing points along the wetland you watch them work the marsh, probing the wet ground with long bills for the rhizomes they live on, black necks bright against pale winter grass. The conservation centre above the marsh keeps telescopes trained on the roost, so you can get close to the birds without pushing them off it. Above it on its spur stands Gangtey Goenpa, founded in 1613 and the largest Nyingma monastery in the country. Out of the courtyard, inside the main hall, the walls close in on you with murals: Buddhas and protective deities in gold, red and deep blue on carved and painted timber. Almost none of that woodwork is original. Beetle larvae ate through the old timber, and between 2001 and 2008 conservators replaced most of it and raised more than a hundred new pillars, copying the detail as they went.
The valley's walk drops from the monastery spur through pine forest, past a mani wall, and flattens out among farmhouses, wooden fences and grazing cattle on the floor. It runs a few kilometres, takes about two hours and is almost all downhill, with the gold roof behind you most of the way. Level marsh-edge tracks carry on between yaks, horses and herders' whistles, and ground this flat is a rare thing in a country of steep gorges. Once a year the courtyard fills for the crane festival, monks dancing masked cham while schoolchildren in white costumes bow and flap their way through the birds' arrival. In summer, with the cranes gone north, the floor is green pasture under dark pine slopes. Those herds are not competing with the birds either. Grazing keeps the dwarf bamboo resprouting across the marsh, and the bamboo is exactly what the cranes come down here to dig for.