Forum Romanum, Rome, eastern neighbourhood. Remains of the Basilica of Maxentius and Constantine, church Santa Francesca Romana, Colosseum and arch of Titus. View from the northern Palatine Hill.

The Basilica of Maxentius and Constantine (sometimes known as the Basilica Nova - meaning "new basilica" - or Basilica of Maxentius) is an ancient building in the Roman Forum, Rome, Italy. It was the largest building in the Forum. The building's northern aisle is all that remains today.

Santa Francesca Romana, previously known as Santa Maria Nova, is a church in Rome, Italy, situated next to the Roman Forum in the rione Campitelli. The church was built in the second half of the tenth century, incorporating an eighth-century oratory that Pope Paul I excavated in the wing of the portico of the Temple of Venus and Roma.

The Colosseum (also known as the Flavian Amphitheatre (Latin: Amphitheatrum Flavium; Italian: Anfiteatro Flavioor Colosseo, is an oval amphitheatre in the centre of the city of Rome, Italy. Built of concrete and stone, it is the largest amphitheatre ever built and is considered one of the greatest works of architecture and engineering.
It´s situated just east of the Roman Forum. Construction began under the emperor Vespasian in 72 AD, and was completed in 80 AD under his successor and heir Titus. Further modifications were made during the reign of Domitian (81–96). These three emperors are known as the Flavian dynasty, and the amphitheatre was named in Latin for its association with their family name (Flavius).
The Colosseum could hold, it is estimated, between 50,000 and 80,000 spectators, having an average audience of some 65,000; it was used for gladiatorial contests and public spectacles such as mock sea battles, animal hunts, executions, re-enactments of famous battles, and dramas based on Classical mythology. The building ceased to be used for entertainment in the early medieval era. It was later reused for such purposes as housing, workshops, quarters for a religious order, a fortress, a quarry, and a Christian shrine.

The Arch of Titus (Italian: Arco di Tito; Latin: Arcus Titi) is a 1st-century A.D. honorific arch, located on the Via Sacra, Rome, just to the south-east of the Roman Forum. It was constructed in c. A.D. 82 by the Roman Emperor Domitian shortly after the death of his older brother Titus to commemorate Titus' victories, including the Siege of Jerusalem in 70 AD. The Arch of Titus has provided the general model for many of the triumphal arches erected since the 16th century.
The Frangipani family turned it into a fortified tower in the Middle Ages. It was one of the first buildings sustaining a modern restoration, starting with Raffaele Stern in 1817 and continued by Valadier under Pius VII in 1821, with new capitals and with travertine masonry, distinguishable from the original.

more on https://en.wikipedia.org/wiki/Basilica_of_Maxentius , https://en.wikipedia.org/wiki/Santa_Francesca_Romana,_Rome , https://en.wikipedia.org/wiki/Colosseum , https://en.wikipedia.org/wiki/Arch_of_Titus , https://upload.wikimedia.org/wikipedia/en/8/8f/Platner-forum-romanum-96-ssh.jpg , https://en.wikipedia.org/wiki/Roman_Forum , https://de.wikipedia.org/wiki/Datei:Map_of_downtown_Rome_during_the_Roman_Empire_large.png http://dlib.etc.ucla.edu/projects/Forum/reconstructions/ForumRomanum_1