много где видела, вот пример из Лиссабона, взрослым вход 10 евро, а местным вообще бесплатноFree admissions:Children up to 12 years of age (except when in a school visit);Lisbon Residents (This tickets can only be acquired at the ticket office, on the day of the visit)Tour operators with RNAAT or RNAVT registry (This tickets can only be acquired at the ticket office, on the day of the visit)On duty members of press with an appointment (This tickets can only be acquired at the ticket office, on the day of the visit)Disabled person’s assistantFor all the price reductions and free admissions, presenting a proof is mandatory.