The Colosseum took ten years to build. Its construction was ordered by the Emperor Vespasian in 70 AD and it was completed under the rule of his son, Titus, in 80 AD.
It had a capacity of over 50,000 and it could be filled in about half an hour.
Spectators could watch gladiators fighting each other, executions, demonstrations of animal hunting, battle re-enactments and even sea battles – the arena would be flooded.
The Colosseum was built on the site of a former lake. Drains were built 8m below the building to deal with the water flowing in from nearby streams.
It has massive foundations which are over 10 metres deep in some places.
Historians haven’t been able to discover the name of the Colosseum’s architect.
The arena in the centre of the Colosseum was covered in sand and contained a number of trap-doors so that wild animals could leap in to spice up the gladiatorial combat.
It is estimated that over 400,000 people lost their lives in the Colosseum.
The Colosseum is the largest of the 200+ amphitheatres built in the Roman Empire.
The outer walls are nearly 50 metres high.
When it rained or when the sun was beating down too strongly on the spectators, a large fabric covering called the velarium was drawn across the Colosseum and anchored by ropes.
The last recorded evidence of Roman gladiators fighting in the Colosseum was in 435 AD.
The Colosseum was severely damaged in an earthquake in 1349. Lots of its stone was used to build churches, hospitals and palaces in Rome. Over the centuries, much of the building’s most valuable materials were stipped away. Today only a fraction of the original building remains intact.
The Colossuem is one of Rome’s key toursit attractions.
During its years of neglect, the Colosseum was home to many exotic species of plants. These probably grew from seeds which were brought in from across the Roman Empire when wild animals were used in the amphitheatre.