ancient buddhist monastery in barikot balo kaley believed to be built in the 2nd century

balo kaley stupa double dome gumbat history barikot swat valley pakistan balokaley kandak buddhist doubledome century monastery tourists architecture archaeology attraction khyber pakhtunkhwa site ancient archaeological mountain government tripartite terrace stupas gandharan cultural culture venue monument buddhism temple ruin heritage historical historic stone asia archeology vihara uddiyana religion buddha religious believed built 2nd