The Jetavana Dagaba
To the east of the Mahathupa lies an enormous brick dagaba, the Jetavana. The dagaba was originally built to a height of 400 feet (120 Metres), making it the 3rd largest building in the world at that time. The two taller buildings were the biggest of the Egyptian pyramids, built two thousand years before.
Mahasena built this massive dagaba in the 3rd Century AD, in a apparent show of strength and support to the Sagaliya sect of the Buddhist order which he followed. This was against strong opposition from the powerful and established orthodox Maha vihara order.
The dagaba is recorded to having a concrete base, and foundations of brick 26 feet deep (12m).