The Kutagarshala represents the spot were Buddha used to stay during the rainy seasons spent at Vaishali. Excavation have exposed three phase of its construction. Originally it was a small chaitya built during Sunga-Kushan period. Subsequently it was enlarged to a lofty temple in second phase during Gupta period. And finally in the third phase the temple was converted into a monastery by providing a number of partition walls during post Gupta period.