(...) The birthday child must be at least 8 years old! To maintain optimal comfort and quality, we welcome up to 12 children per birthday. (...) Included in base rate are: entry for all guests, a guided tour of the various exhibits as well as a set table and chairs for you in the cafeteria. It is up to you to bring food and drinks. 

It is also possible to plan a guided tour of the exhibits only. (...) Birthdays are organized Tuesdays through Saturdays. Reservations are mandatory.