In ancient times, it was known as Kasia, a celebrated center of the Mallas kingdom of ancient India. Later, it would be known as Kusinara, one of four holy sites for Buddhists. At this location, near the Hiranyavati River, the Indian spiritual teacher Gautama Buddha was cremated, had passed and attained Parinirvana (complete Nirvana).
Many of the stupas and viharas in ruin here date back to 3rd century BC - 5th century when prosperity was at peak. The Mauryan emperor Ashoka is known for contributing to significant construction at this site.
There was a silence of more than half a millennium at Kasia. Due possibily to violent invasions, Kushinagar lost its vitality and eventually was neglected. The notable Buddha Temple, when later discovered, was covered in a 40' high mound of bricks surrounded by a dense thorny forest. After E Buchanan, an officer of east India Company, arrived in the course of his survey-work, H. H. Wilson, in 1854, made the suggestion that the identity of Kushinagar and Kasia were the same. Work resumed around 1861-1862 when General Alexander Cunningham, an archaeological surveyor, would prove the site to be of Gautama Buddhas passing. A British officer named Mr. A.C.L. Carlleyle followed suit. In the last century, excavations were underway and many important remnants of the main site such as the Matha Kua and Ramabhar stupa were unveiled.
Today, Kushinagar is a frequented pilgrimage site for tourists and temples have been constructed by Chinese, Sri Lankan, Thai, and Japanese Buddhists along the ruins of monasteries and stupas. For Buddhists, this is one of four pilgrimage sites designated by Gautama Buddha, the other three being Lumbini, Bodh Gaya, and Sarnath.