Around 1330 C.E. a slender, lotus bud tower enshrining a Buddha relic was built atop Ramkhamhaeng’s pyramid in the center of the city, thereby turning it into a Buddhist stupa. In the early 1340s, Si Satha expanded the stupa to enshrine two Buddha relics he brought back from Sri Lanka where he had resided for a decade. He also added four axial towers. More than two hundred buildings were constructed around the stupa itself, which became known as Wat Mahathat, the Monastery of the Great Relics. This pattern of constructing a reliquary stupa or Cetiya as the symbolic and ceremonial center of the kingdom typiies the development of Tai city-states.