The drive east crosses Dochula Pass, where 108 memorial stupas stand against a Himalayan skyline. On a clear day the high peaks are visible to the north. The descent into Punakha brings a sharp change in climate - warmer, more subtropical, with rice paddies replacing pine forest. Chimi Lhakhang, the Temple of Fertility, sits in the middle of this landscape. Punakha Dzong, built at the confluence of two rivers, is arguably the most beautiful fortress in the country.