Short answers, pulled from the story.
The region now known as Kushinagar derived its ancient name from the abundance of kusha grass that once defined the landscape. Alexander Cunningham noted that this specific vegetation gave the place its name rather than any royal lineage or deity.
Gautama Buddha reached his eightieth year during a journey from Rājagŗha to Pāvā before falling ill after eating sūkaramaddava at Pāvā. He crossed the Kakkuttha River which is now called the Khanua River to reach a grove of sala trees where he laid himself down to rest and died seven days later according to the Mahāparinibbāna Sutta.
Alexander Cunningham performed archaeological excavations at the Matha Kuar shrine in 1861-1862 while his colleague Archibald Carlleyle exposed the Mahaparinirvana stupa in 1876. J. Ph. Vogel conducted further campaigns between 1904 and 1907 uncovering vast amounts of Buddhist materials.
Ashoka built a stupa and placed a pillar to mark Buddha's attained parinirvana in Kushinagar during the third century BCE. Hindu rulers of the Gupta Empire enlarged the stupa and constructed a temple containing a reclining Buddha statue from the fourth to seventh centuries.
The Parinirvana Temple houses a 6.10-metre-long statue made of a single block of red sandstone that represents the Buddha reclining on his right side with his head to the north. A copper plate found during excavations contained text stating Haribala installed the statue inside the Nirvana Chaitya.
On the 13th of May 1994 the area became a new district of Uttar Pradesh separate from Deoria according to the 2011 Census of India which recorded a total population of 22,214 people. Literacy rates reached 68.2 percent with male literacy at 73.3 percent and female literacy at 62.7 percent.