Below the surface of the University of Chicago lies a facility -- concealed under an impressive piece of modern architecture -- that houses the wisdom of the ancients. At the push of a button, a visitor can utilize state-of-the-art technology to bring forth this knowledge for his or her own scholarly pursuits.
It's pretty much a Batcave for the Ph.D. crowd.
The Joe and Rika Mansueto Library, which opened Monday, is Chicago's answer to a problem that many universities have encountered in recent years -- too many volumes and not enough library space. Faculty members adamantly opposed moving books, particularly monographs, off-site, and building a new above-ground library seemed so 1970s. So the answer -- the brainchild of Chicago architect Helmut Jahn -- was to dig down.
Chicago's new library opens at a time when several universities are moving volumes to off-campus , high-density storage facilities -- a contentious issue on some campuses . Chicago's decision represents a different and perhaps more costly solution to the problem those campuses are facing. While the new design eliminates stacks in favor of high-density storage and makes room for other uses of campus and library space, it maintains the convenience, as well as the psychological comfort, of keeping those volumes close and on campus.
"Reality shows that you cannot do your research well having materials off-site," said Judith Nadler, university librarian. "The cost of what you would give up in terms of research, studying, and teaching outweighs the cost of the building."
The Mansueto library is an expansion of the Regenstein Library, which houses the university's volumes on the arts, social sciences, and humanities, and will be connected to the old building. The underground facility is large enough to hold 3.5 million volumes. That's on top of the 9 million volumes that the university's other libraries can hold, most of them in stacks.
High-density storage is not a new tactic for university libraries. In fact, numerous universities already use such technology . Chicago's innovations are placing the facility underground and adopting an automatic retrieval system  traditionally used in industry to bring books to the surface. At the push of a button, large cranes pull cases off the shelves, which are then brought up to librarians. The whole process should take about five minutes, Nadler said.
One floor of the library is above ground and will serve as a reading room and preservation and digitization center, encased in a 35-foot glass dome.
The decision-making process that led to the Mansueto library was extensive and goes back almost a decade, faculty members and librarians said. When the university decided it had to expand its library space and considered its options, faculty members argued  that any decision that eliminated their ability to peruse the stacks would harm their research capability.
While the new library puts some works out of sight, the university has thoroughly considered which works will go underground. They include serial works that have already been digitized, special collections that were not able to be browsed in the first place, and large collections of state documents. Plus, there will still be more than 4 million books in the Regenstein library to be browsed in stacks.
Andrew Abbott, a sociology professor who was heavily involved in the library's planning, said the extensive collaboration led to a decision that faculty members have supported.
"If there's a faculty member at Chicago who is interested in library research and who is not happy about Mansueto, I haven't met him or her," he said. "We have avoided precisely that disaster which our colleagues elsewhere have endured."
Abbott sees the combination of extensive browsable stacks with high-density, on-site storage as an ideal solution. But the university's method might not be as feasible on other campuses, particularly those with less cash on hand. The new library's construction was bolstered by a $25 million gift from the library's eponyms , the chairman and CEO of investment research firm Morningstar Inc and his wife, who both graduated from Chicago.
Syracuse University, which is facing a shortage of space, will likely spend about $5 million on a high-density storage facility about 2 miles from the university's central campus, said Suzanne Thorin, dean of libraries. That facility will house about 1.6 million volumes in its first stage. The University of Denver is planning on spending about $32 million to renovate its Penrose Library to make more study and group-meeting room. The price includes the $3 million purchase of a storage facility about 10 miles off campus.
Nadler said Chicago's underground facility was comparable in price to an off-campus storage facility when the university explored its options. She said the money saved through the project would make costs even out in the end: unlike an off-campus site, the automated underground facility will not require additional workers to retrieve books or provide additional security. The university would also save on the costs of climate control and transportation.