Archaeological evidence of Lord Buddha’s last existence still stands strong and numerous even 2500 years after his demise in 483 BC.
http://whc.unesco.org/en/list/666
http://en.wikipedia.org/wiki/Lumbini
http://what-buddha-said.net/library/DPPN/l/lumbini.htm
http://www.buddhanet.net/e-learning/buddhistworld/lumbini.htm