以官网信息为准，以下是他家的免费条件： https://www.coopculture.it/en/colosseo-e-shop.cfm FREE Citizens under 18 years old from European Union and no-EU countries. Italian permanent teachers or with fix-term contract upon presentation of the suitable certification issued by the schools. The Archaeological Park of the Colosseum has determinated some days durning the year with free admission and without pre-sale: 9th of May 5th of June OTHERS FREE CONDITION European Union’s tour guides in the exercise of their professional activity; European Union’s touristic interpreters in the exercise of their professional activity; Employees of the Ministry for Cultural Heritage and Activities; Members of ICOM (International Council of Museum); Members of ICCROM (International organization for conservation of cultural heritage); groups of students from public and private schools of the European Union, together with their teachers upon reservation and within the quota established by the head of the school; Teachers and students of Architecture, Conservation of Cultural Assets, Learning Sciences and degree courses in Literature with Archeology or Art-History subject areas in the universities and art academies and enrolled in the respective improving schools, Specialist Studies and PHD’s of the above-mentioned courses of EVERY member State of the European Union. The ticket is released to the students by showing a certificate of registration in the current academic year; Socrates and Erasmus students of the above-mentioned degree courses; Art-History teachers in High-schools; Students of the following schools: Central Institute of Restoration, Opificio delle Pietre Dure, School for Mosaic Restoration; Journalists enrolled in the national register and journalists coming from any other country, in the performance of their duties and upon presentation of a suitable document proving the professional activity carried out; People with disabilities and one family member or a helper belonging to the health and social assistance service; Volunteers who carry out promotion and dissemination activities of the Cultural Heritage, on the basis of the agreements concluded with the Ministry, according to art. 112, paragraph Project “Born with Culture” (agreement with a three-year validity: from 29/11/2018 to 29/11/2021): a cultural passport for every newborn, that allows free entrance to the Park to the child and the family (up to 2 accompanying persons) until the baby’s first birthday. Any right to a reduction or to a free admission has to be proved by the ticketing staff.
你说的免费信息可能也是存在的，因为中间提到“The service is not provided on the free Sundays.”
另外，他家也说道：Free tickets cannot be booked online, but only by phone via call center. Otherwise, you can directly collect free tickets at the ticket office the day of the visit paying the reservation fee. 意思是免费票不能在线订，这可能是你在线看到是全价的原因。