Celemantia (or Kelemantia) was a Roman castellum and settlement on the territory of the present-day municipality Iža. It is the biggest known Roman castellum in present-day Slovakia. It was a part of the Roman Limes, the frontier-zone of the Empire.
A Germanic settlement 'Celemantia' in this area is mentioned by Claudius Ptolemaios in the 2nd century AD. It can be identical with the remnants of a civil settlement found next to the castellum or with another unknown settlement or, as some historians assume, it is the name of both the castellum and the remnants of the civil settlement.
The construction of the castellum started in the latter half of the 1st century. It was conquered during the Marcomannic Wars (166-180) and burned down by Germanic tribes, and was rebuilt later. It ceased to exist around 400 (beginning of the Migration Period). The ruins were very well visible up to the late 18th century, but afterwards people used stones from the constructions to build the fortress and other buildings in Komárno.
According to a local legend, a Roman soldier, Valentin, kept his mistresses in the fortress. The fictitious story explains the origin of the name Leányvár, meaning Girl Castle in Hungarian. However the name probably refers to the fact that the ruins of the castle were donated by King Béla IV of Hungary to the Dominican nuns of Margitsziget who later built a small fortress among them.
References:The Arch of Constantine is situated between the Colosseum and the Palatine Hill. It was erected by the Roman Senate to commemorate Constantine I's victory over Maxentius at the Battle of Milvian Bridge in 312. Dedicated in 315, it is the largest Roman triumphal arch. The arch spans the Via triumphalis, the way taken by the emperors when they entered the city in triumph.
Though dedicated to Constantine, much of the decorative material incorporated earlier work from the time of the emperors Trajan (98-117), Hadrian (117-138) and Marcus Aurelius (161-180), and is thus a collage. The last of the existing triumphal arches in Rome, it is also the only one to make extensive use of spolia, reusing several major reliefs from 2nd century imperial monuments, which give a striking and famous stylistic contrast to the sculpture newly created for the arch.
The arch is 21 m high, 25.9 m wide and 7.4 m deep. Above the archways is placed the attic, composed of brickwork reveted (faced) with marble. A staircase within the arch is entered from a door at some height from the ground, on the west side, facing the Palatine Hill. The general design with a main part structured by detached columns and an attic with the main inscription above is modelled after the example of the Arch of Septimius Severus on the Roman Forum.