While visiting Kathmandu in 250 BC, Emperor Ashoka erected four Ashok Stupas which manifests the four corners or directions of Patan. The Stupas have been constructed according to Buddhist Architecture. The stupas have been regarded as a demonstration to ancient architectural tradition. It has a circular base and hemispherical shaped dome. Each of the four stupas is different from another. On the full moon of August, Buddhist and Tibetian pilgrims walk all around the four stupas in a single day.