Location from harry-potter-order-of-the-phoenix by
The vast Hogwarts library -- this year under the shadow of Umbridge's approved curriculum, with Hermione pulling books on defensive magic before they can be restricted.
The library is where Hermione researches everything -- defensive spells for the DA, legal precedents for Harry's hearing, and the jinx she puts on the DA membership parchment. Umbridge's influence hasn't quite reached Madam Pince's domain, possibly because Pince is more territorial about her books than any High Inquisitor could hope to be. The Restricted Section remains roped off, its books occasionally moaning, and the students who need to learn to defend themselves find what they need in the regular stacks -- because the best defensive magic isn't restricted. It's just ignored by a curriculum designed to keep students helpless.
Thousands of shelves in towering rows, lit by lamps on each table. The Restricted Section behind a rope at the back. Madam Pince patrols the aisles like a vulture. Reading tables and chairs fill the central space.
Also known as: the Library, Hogwarts Library, the Restricted Section