Porte Mars is an ancient Roman triumphal arch in Reims. It dates from the third century AD, and was the widest arch in the Roman world.
The arch stands 32 metres long and 13 metres high. It was named after a nearby temple to Mars. The arch has many highly detailed carvings on its exterior and on the ceilings of its three passageways. Local folklore says that the inhabitants of Rheims built the arch in gratitude when the Romans brought major roads through their city. It served as a part of castle of archeveque and a city gate until 1544 was closed of it. In 1817, the buildings around it were removed, bringing the arch into full view.References:
The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.