The Dhamek stupa at Sarnath, near Varanasi, is a massive one. It was built in 500 CE, replacing another structure built in 249 BCE. It's said that the Buddha gave here his first sermon to his first 5 brahmin disciples after attaining enlightenment.
Nowadays there are still sermons here, very impressive! See my next photo! 
That's a long time ago yet it still looks stable. Thanks for sharing.
Thanks for watching, it was built to last and so far it did.