Post breakfast, drive toward Punakha, stop at Dochula Pass (3,100 m), where on a sunny day, you can get stunning views of the Himalayan ranges. The Dochu La Pass is probably the best known mountain pass in Bhutan.
Another striking feature at the pass are the 108 Druk Wangyal Khangzang Chortens, that were built for the well-being of all sentiment beings on earth. The 108 Chorten were built as a tribute to the Kings of Bhutan for their selfless service and leadership they offer to the people of Bhutan.
Continue drive towards Punakha and stop at Lobesa village and have lunch(on your own) before going for a short hike to Chimi Lhakhang (Temple of Fertility), it is dedicated to Lam Drukpa Kuenley (Divine Mad Man) and is the place from where Phalluses originated as the symbol of fertility and protection and can be seen everywhere in Bhutan, on house walls and roofs and altars. Childless couples usually go to this temple to get blessings so that they conceive and are blessed with a child.
(NOTE: The temple and has some sexual depictions. You may want to reconsider visiting this place if you are not comfortable with children seeing these)
Then drive to Punakha Dzong: The Punakha Dzong or the Pungtang Dechen Phortang Dzong is located at the confluence of the Mo Chhu and the Po Chhu River, combine to form the Puna Tsang Chu which in turn is a tributary of the mighty Brahmaputra River.
Overnight stay at Punakha.