The Porta Nigra (“Black Gate” in Latin) is the only surviving Roman city gate in Trier. It was built as the northern gate into the city at the time when Trier’s city wall was erected, around the year 170 CE. While not quite finished as initially intended, it has survived more or less intact through the ages, even as the city’s other three gates were demolished and used as quarries in the middle ages. Its survival may owe its thanks in part to having been the home of St Simeon the Hermit in the middle ages and later for a while converted into the collegiate church of St Simeon. Next to the Porta Nigra was then also built the Simeonstift monastery in his honor. The monastery today houses Trier’s city museum. Porta Nigra’s church superstructure was partially demolished on Napoleon’s orders to restore the gate to (nearly) its original Roman shape, as we see it today. For some reason, the gate’s eastern tower was not rebuilt to its original height, which gives it it’s current curiously asymmetrical shape.