There is no charge to enter the Colosseum in certain specific circumstances. For example:
1. Free admission days: There are days when admission is free for all, such as the first Sunday of each month.
2. Under 18s: EU citizens under the age of 18 can enter free of charge, but must present proof of identity.
3. Teachers and students: Some teachers and students may be entitled to free or discounted admission, depending on the regulations in force.
4. Disabled persons: Persons with disabilities and an accompanying person may enter free of charge.
5. Special events: On some occasions, there may be events or initiatives that provide free admission.
It is always advisable to check the Colosseum's official website or contact the information office for up-to-date details on admission policies.