Buddhism is a religion that teaches self-sacrifice and self-restraint to end suffering by living without desires. Key sites and structures developed around relics of Buddha, including the stupa at Sanchi containing his relics. Asoka spread Buddhism across India and to other countries in the 3rd century BC. Stupas and chaityas were built to house relics, taking various forms over the centuries. The Ashokan pillar at Sarnath features carvings symbolizing the Wheel of Law. Monasteries and viharas provided living spaces for monks around stupas.