If you're allergic to greasy smoke, don't go. Consider bringing a flashlight if you do, though. It's very, very dark inside--not to mention truly huge. It contains many priceless works of art and religious relics, and is tended by Buddhist monks and some Chinese soldiers, and don't assume you can tell the difference. Security is extremely lax, though, so please, PLEASE, don't touch the books and relics. So many artifacts have been destroyed over the years, and what is left is truly irreplaceable.