Officially the Harold T and Vivian B Shapiro Undergraduate Library, but more commonly known as the UGLi, the Undergrad was built in 1957. It was sometimes known as the ugliest building on campus until it was renovated in 1995. The library's first floor lobby received a renovation that began in October 2010 and completed in February/March 2011. It stands immediately southeast of the Hatcher Graduate Library; a bridge connects the third floor of the Shapiro building to the second floor of Hatcher. There was also a connection, on the opposite side of the building, from the third floor of Shapiro to West Hall, which has now been closed.
The outside return slot for UGLi books is located along the west side of the building, not far north of South University St. The UGLi is open 24 hours, 7 days a week: 12am-12am. After midnight, access is restricted to UM people.
The main entrance to the UGLi faces north, towards the Diag. As you enter, on the left-hand side of the building is a non-secure lounge for food and email-checking, as well as newspaper-reading. You will see many flyers and posters for UM and community events. The magnetic security devices where you walk in contain immediately within a browsing section with lots of romance and SF novels. Reference and call numbers P are on the ground floor. The eastern wall of the ground floor contains many comfy chairs and footrests, and you will find many students studying or sleeping there at all hours. All floors of the UGLi have many tables for working alone or in groups; floors 1 and 3 have computer banks.
The Science Library 3rd floor has a western walkway to the second floor of the GradLi, which oddly enough moves upwards in that direction.
The building contains four libraries:
- the Shapiro Undergraduate Library, occupies the basement, first, and second floor. Its collection consists of texts in all disciplines targeted for lower-division (first- and second-year) students. The Undergrad also houses the University Reserves collection, providing texts for many classes on shortened loan periods. UGL home page
- the Askwith Media Library, formerly the Film and Video Library, is one of the largest of its kind anywhere. It holds over 25,000 titles on 16mm, videotape, DVD, and other formats in a mid-sized room on the second floor and in remote storage. Askwith home page
- the Shapiro Science Library, holding upper-division and graduate-level science texts and journals, occupies the third and fourth floors. SciLib home page
- the Internet Public Library, with administrative offices on the fourth floor, provides reference services via the Internet worldwide. The IPL is being moved to a consortium of Information schools, so not all services are located here anymore. 
A virtual tour will get you oriented.