The Amphitheatre of the Three Gauls is located in which country?

The Amphitheatre of the Three Gauls of Lugdunum (Lyon, France)) was part of the Sanctuary of the Three Gauls dedicated to the cult of Rome and Augustus celebrated by the 60 Gallic tribes when they gathered at Lugdunum. Stones bear the names of Gallic tribes (Arverni, Tricasses, Bituriges) confirming its identification as federal sanctuary.

Excavations have revealed a basement of three elliptical walls linked by cross-walls and a channel surrounding the oval central arena. The arena was slightly sloped, with the building's south part supported by a now-vanished vault. The arena's dimensions are similar to those at the arenas at Nîmes and Arles, though with a smaller number of rows of seats.

The amphitheatre was expanded at the start of the 2nd century. Two galleries were added around the old amphitheatre, raising its width from 25 metres (82 ft) to 105 metres (344 ft) and its capacity to about 20,000 seats. In so doing it made it a building open to the whole population of Lugdunum and its environs. Historians identify the building as the site of Saints Blandina and Pothinus's martyrdoms as part of the persecution in 177 and a post in the middle of the arena commemorates this event along with Pope John-Paul II's visit to Lyon in 1986.