The great amphitheatre begun by Vespasian is finished and dedicated by his son Titus with games. Suetonius does not give the year.
Having dedicated his amphitheatre, and built some warm baths close by it with great expedition, he entertained the people with most magnificent spectacles.
The Colosseum is the largest ancient amphitheatre ever built and, though much ruined, is still a renowned symbol of Imperial Rome.
Based on Wikipedia: Colosseum
It is the largest ancient amphitheatre ever built, and is the largest standing amphitheatre in the world.
Although substantially ruined by earthquakes and stone robbers taking spolia, the Colosseum is still a renowned symbol of Imperial Rome and was listed as one of the New 7 Wonders of the World.