This monument, square on plan, measuring 18.29 m along each side, represents the main shrine where the Buddha used to sit in meditation for three months during the rainy season. According to Hsuan-tsang it was 61 m high. The style of decoration and moulding indicate that the monument was raised in the Gupta period. The concern pavement round the monument was added later when the brick walls were also added inside the main chamber to give support to the roof.