The Citadel composes most of the city of Kom in Omnia. It is a great labyrinth of churches, houses, schools, markets, dormitories, gardens and torture-chambers (now thankfully obsolete) centred around the Temple of the Great God Om.
Thanks to the work of the Prophet Brutha It now also boasts the biggest non-magical library in the world, with an enviable collection of theological works. In fact, there are 1,283 different Bibles and Holy Books, each of which comes with the solemn guarantee that it is the Truth and therefore the only book anyone need ever read. As Didactylos said, you have to laugh.