Erected in AD 175 in honour of Marcus Aurelius, this 16.5m-high Roman triumphal arch stands very near where the columns of a Roman theatre and the vestiges of an aqueduct (all still visible) were discovered in the late 19th-century.

　　The site, which attests to the importance of Besançon as a site of Gallo-Roman civilisation, was restored as an 'English-style architectural garden' in 2006.