This is the spot of the Hadrian Gate, I understood they simply gave this name to an existing gate when Hadrian was about to visit the town.

It lies on the southern end of the main street; only its base is still in place.

Correspondent: J.M.Criel, Antwerpen.
Source: ‘Lycie’ – Cevdet Bayburtluoğlu & Personal visits (1989, 2006)