Answer: (Harry Potter right?) Professor Trelawney's subject was Divination. She teaches different methods of predicting the future, though some aren't always exact. Divination sometimes is not considered real magic, because the event never really happens; but keep in mind that it can be in a span of a day, to years and years. Her classroom, described as: "At least twenty small, circular tables were crammed inside it, all surrounded by chintz armchairs and fat little pouffes. Everything was lit with dim, crimson light; the curtains at the windows were all closed, and the many lamps were draped with dark red scarves. It was stiflingly warm, and the fire which was burning under the crowded mantelpiece was giving off a heavy, sickly sort of perfume as it heated a large copper kettle. The shelves running around the circular walls were crammed with dusty-looking feathers, stubs of candles, many packs of tattered playing cards, countless silvery crystal balls and a huge array of teacups" makes readers visualise how odd it really is, how bizarre the atmosphere feels. It is a dark and mysterious subject indeed, just looking at how the classroom is arranged. The location of the classroom is also really weird, because you have to pass through many things to get there. I personally don't think that the room itself is that unusual, but TRELAWNEY IS!
I hoped you get an idea of what I mean <3