Question: The Cirque de Gavarnie is compared to what oval amphitheatre built of concrete and sand is the largest amphitheatre ever built?
Sentence (from "Colosseum"): The Colosseum or Coliseum ( ), also known as the Flavian Amphitheatre (Latin: "Amphitheatrum Flavium"; Italian: "Anfiteatro Flavio" ] or "Colosseo" ] ), is an oval amphitheatre in the centre of the city of Rome, Italy.
Relevant evidence: Yes