I've been having trouble picturing the layout of 12 Grimmauld Place in my head. Specifically, in the fourth chapter of the Order of the Phoenix,
The three of them looked cautiously over the banisters. The gloomy hallway below was packed with witches and wizards, including all of Harry’s guard. They were whispering excitedly together. In the very center of the group Harry saw the dark, greasy-haired head and prominent nose of his least favorite teacher at Hogwarts, Professor Snape. Harry leaned farther over the banisters. He was very interested in what Snape was doing for the Order of the Phoenix. . . . A thin piece of flesh-colored string descended in front of Harry’s eyes. Looking up he saw Fred and George on the landing above, cautiously lowering the Extendable Ear toward the dark knot of people below. A moment later, however, they began to move toward the front door and out of sight.
This passage implies there is a large gap between the staircases that continues up until at least the third floor. On the other hand, it says that Fred and George are on the landing above, implying there aren't any landings between floors. I can't picture a stair configuration that allows for viewing down multiple floors and also has stairs that don't turn or curve between floors. Am I taking this part too literally or just not being imaginative enough about staircases?