the inside view of the corridor of the balo kaley double dome stupa built in the 2nd century

balo kaley stupa dome gumbat gumbatuna history swat valley pakistan balokaley buddhist monastery architecture archaeology khyber pakhtunkhwa site masterpiece ancient archaeological shrine stupas landmark gandharan corridor venue old buddhism temple ruin heritage stone sculpture archeology vihara religion buddha religious famous inside view window light air ventilation ceiling arch door gate double built 2nd century