The Battle of Plataea was the last major battle of the Persian wars. It happened in the year 479 BC. This battle went on for days. The war was so intense that the Persians would even poison the Greeks water supply so they could win. Unfortunately for them they did not win.
After the war, Greece was able to regroup itself and make a group called the Delian league that would protect people from the Persians while making Athens beautiful.
Persia on the other hand, stayed as it was. They did not gain any land from the war. They also weren't such a big threat to the Greeks anymore.