The Atrium is a very long and splendid hall that serves as the main entrance and central hub for the British Ministry of Magic. The floor is made of highly polished, dark wood, so shiny that it reflects the occupants like a dark lake. The ceiling is a peacock-blue color, inlaid with shimmering golden symbols that constantly move and change, resembling a celestial noticeboard. Set into the left-hand wall are numerous gilded fireplaces, which allow witches and wizards to travel directly into the Atrium using the Floo Network; green flames signify an arrival. The right-hand wall contains an equal number of fireplaces for departures. Halfway down the hall is a security desk, where visitors must present themselves to guards like Eric Munch and have their wand weighed and registered before proceeding. The centerpiece of the Atrium has changed according to the political climate:
At the far end of the Atrium, a set of golden gates provides access to a hall containing at least twenty golden-gated lifts, which transport employees and visitors to the various departments on the levels below.
The Atrium is the setting for several pivotal events in the series. In Harry Potter and the Order of the Phoenix, Harry Potter visits the Atrium for the first time on his way to his disciplinary hearing, accompanied by Arthur Weasley. The hall serves as the backdrop for the climactic duel between Albus Dumbledore and Lord Voldemort. During the battle, Dumbledore magically animates the golden statues of the Fountain of Magical Brethren to shield Harry and attack Voldemort. The fountain is ultimately destroyed by a powerful curse from Voldemort just before he is seen by Cornelius Fudge and other Ministry officials, forcing them to finally accept his return. In Harry Potter and the Deathly Hallows, Harry Potter, Ron Weasley, and Hermione Granger infiltrate the Ministry under the influence of Polyjuice Potion. They arrive in the Atrium to find it transformed by the “Magic Is Might” monument, a chilling symbol of the new world order. Their escape from the Ministry is complicated when Corban Yaxley grabs onto Hermione as she Disapparates from the Atrium, thereby compromising the secret location of Number Twelve, Grimmauld Place.