P.T. Tso, sometimes called Paradise Lake or Pankang Teng Tso, is a glacial lake about 17 km from Tawang town, accessible on a rough road through deep forest and open hillside. The lake is strikingly beautiful: a high-altitude reservoir of blue-green water ringed by rocky peaks, with yaks sometimes grazing on the shore. The drive there is arguably as rewarding as the lake itself, passing through rhododendron forests that bloom spectacularly in April and May.
Permits are required to visit P.T. Tso as it falls in a restricted border zone. Arrange them in advance through the Deputy Commissioner's office in Tawang. A local guide or jeep hire is the easiest approach; the road is not suitable for small cars. Best visited between April and October — in winter the road is snowbound and the lake may freeze.