what is your reason about ?
Every country has its own rich culture, but the most ancient and interesting for me are cultures of Egypt, Greece, Rome and China...:)))
There are many fascinating cultures that have existed for many years that are just as great as that of China ,India,Egypt,Greek and Italy.
China. Hands down!
I'd like to say about the great civilizations which formed contemporary cultures.
They are Ancient Egypt, Ancient Rome, Russia, Byzantium, China, The Indus Valley Civilization ( the Harappan Civilization), The Persian Empire.
If I missed a few I hope someone will correct me.
Japan, China, Great Britian, and Germany.
They make impacts in the world.