The ‘Great Stupa’ at Sanchi is the oldest stone structure in India and was originally commissioned by the emperor Ashoka the Great in the 3rd century BCE. Today, it is a UNESCO World Heritage Site. Its nucleus was a simple hemispherical brick structure built over the relics of the Buddha. It was crowned by the chatra, a parasol-like structure symbolising high rank, which was intended to honour and shelter the relics. It has four profusely carved ornamental gateways and a balustrade encircling the whole structure.