Swayambhunath stupa (UNESCO World Heritage Site) of Kathmandu, Nepal:

Swayambhunath Stupa is one of the holiest Buddhist Chaityas in Nepal is resting on a hillock 3 km west of Kathmandu. With numerous shrines and monasteries on its premises, the stupa is the oldest of its kind in Nepal. The stupa is not a man made stupa but is said to have evolved unexpectedly and spontaneously when the valley was created out of a prehistoric lake more than 2,000 years ago.

  Bouddhanath stupa (UNESCO World Heritage Site) of Kathmandu, Nepal:

As soon as you land at the Tribhuvan International Airport you will see Bauddhanath which is one of the most striking landmarks in Kathmandu and is located 8 km to the east of downtown Kathmandu. Famous as center of Tibetan Buddhism the stupa is the largest stupa in the Kathmandu Valley.