We begin our journey in the expansive underworld of Widener Library: the stacks. Seemingly never-ending rows of books and pin-drop silence give an eerie feel to the depths of the library.

Though more than three million volumes are held in the Widener stacks, this is only a small portion of the Harvard Library’s total collections, which span 20 million volumes, 400 million manuscripts, 10 million photographs, and one million maps.

Research librarian Sarah DeMott leads us through the tunnels beneath Harvard’s campus. Extending across buildings, these tunnels function partially as storage spaces and allow easy travel through the stacks.

On a half-floor of the stacks, DeMott combs through the extensive research collections of Widener Library. The stacks are built as half-floors to maximize use of space, since the building’s donation rules forbid upwards expansion.

DeMott peruses one of many books containing British government documents. International government documents are available in both Widener and Lamont, which house research collections and general materials, respectively.

We peek into Widener’s massive section on Islamic Studies. There — and throughout the library — mountains of materials are queued to be parsed through.

Red emergency telephones are located throughout the 50 miles of bookshelves in Widener.

On Widener’s third floor, DeMott walks into a specialty room featuring publications from the Islamic Studies department. This floor is home to various departments and their resources, which are available upon request.

Traveling through the tunnels, we find ourselves inside Lamont’s microfiche stacks. DeMott demonstrates the use of a microfiche scanner with an article about the Black Panther Party. Such materials can be accessed by the public by filing a request to see government documents.

At Houghton Library, we are welcomed by Librarian for Scholarly and Public Programs Peter Accardo. Every Friday, Accardo holds a public tour of Houghton’s closed rooms on the second floor, including the John Keats Room. Opened in 1942, Houghton is the home of Harvard’s rare books and manuscripts.

Branching off of the Keats Room is the Emily Dickinson Room. Housing original furniture from the Dickinson Home in Amherst, the room contains Emily’s writing table and the chest where her sister Lavinia discovered her poems posthumously.

Accardo brings us into the William King Richardson Library Room, which houses singular works such as authentic texts of Jane Austen, Walter Whitman, and Homer — in the original Greek. All of these and other treasures are accessible upon request.

The tour concludes in the Richardson Room with a lively discussion between DeMott and Accardo on the future of Houghton. Modern digitization of materials and innovative book scanning are hot topics, even when surrounded by the most antique texts.