HAVE you ever seen the world's largest mechanical tracker pipe organ? Do you know how a well-equipped grand theatre can also be an international conference hall with infra-red simultaneous interpretation system? Do you know how a studio theatre can be viable to variable stage formats? The daily tours organised by the Hongkong Cultural Centre will unveil such rarely-known details of the premier performing art venues to visitors in a fascinating and interesting way. Tours are held at 12.30 pm and 4 pm, with both English and Chinese commentaries. Charges are $10 for adults and $5 for children, students, senior citizens, as well as group bookings of 25. Tickets are on sale at the enquiries counter in the Main Foyer of the Hongkong Cultural Centre. For telephone reservation or more information, call 7342009.