Inside the world's largest college dorm, a 1.4 million-square-foot Naval Academy building with over 4,600 beds and its own ZIP code

Bancroft Hall at the US Naval Academy in Annapolis, Maryland.

Jonathan L.

Correa/Planet Pix/ZUMA Wire via Reuters Connect Bancroft Hall at the US Naval Academy is the largest single college dormitory in the world.

It features 4,663 beds, 33 acres of floor space, and 4.8 miles of hallways.

Rules govern which doors midshipmen are allowed to walk through and how they organize their rooms.

Bancroft Hall at the US Naval Academy in Annapolis, Maryland, is named for former Navy Secretary George Bancroft, but to the midshipmen who call the dormitory home, it is affectionately known as "Mother B." The largest single college dormitory in the world, Bancroft Hall, houses all roughly 4,400 midshipmen throughout their four years of study at the elite military academy.

Bancroft Hall's center section and first two wings, designed by Ernest Flagg, a Beaux-Arts architect known for his grand, classical designs, were completed in 1908.

The dormitory was expanded in 1921, 1941, and 1961 and now features eight wings.

Bancroft Hall was named for the founder of the Naval Academy, George Bancroft, who also served as the Navy Secretary. gregobagel/Getty Images/iStockphoto The enormous 1.4-million-square-foot complex houses 1,639 dorm rooms and 4,663 beds, and contains 33 acres of floor space and 4.8 miles of hallways, which midshipmen refer to by their maritime term, "passageways." The dorm is so big that its internal post office uses the unique ZIP code, 21412.

Incoming freshmen, known as "plebes," march into Bancroft Hall through the center doors after their Oath of Office Ceremony on Induction Day , the first official day of Plebe Summer before the academic year begins.

From then on, midshipmen are not permitted to walk through the center doors until after graduation. (Civilians, officers, and non-midshipmen are allowed to use the center doors.) Plebes march into Bancroft Hall through the center door after taking part in their Oath of Office Ceremony on Induction Day at the US Naval Academy.

Kevin Dietsch/Getty Images The front doors of Bancroft Hall open into a decorative rotunda accessible to visitors.

Memorial Hall, a space honoring fallen alumni of the US Naval Academy, is publicly accessible through the staircase in the rotunda.

Bancroft Hall also features student services, including gyms, a uniform store, a bookstore, a tailor, a cobbler, laundry rooms, and dental and medical facilities.