A warehouse big enough to store eight million books and maps for Oxford University's overflowing Bodleian Library has been unveiled.
The £26m site near Swindon, Wiltshire, has 153 miles (246km) of shelving.
The library, which is entitled to a copy of every book published in the UK, had been running out of space to store works for decades.
With 1,000 new books arriving each day, the head librarian said the situation had become "desperate".
The new warehouse has enough space to support the Bodleian for the next 20 years.
Over the next year, nearly six million books and more than 1.2 million maps will be transferred from Oxford to the storage facility.
It will be predominantly low-usage books and maps which will be stored at the 13-acre site, 28 miles from Oxford.
More popular items and special collections - including four original manuscripts of the 13th century Magna Carta - will remain in Oxford.
The warehouse, which can be expanded in future if needed, has 3,224 bays with 95,000 shelf levels.
There are 600 map cabinets which will hold 1.2 million maps and other larger items.
The floor space of the unit is the same as 1.6 football pitches - although the total shelf surface area is 10 times that, thanks to high-density shelving.
Students have been told that if they order a book from the new unit by 1000 in the morning, it should be delivered to the Oxford reading room of their choice by 1500 that afternoon.
Library staff will use forklift trucks to retrieve books which will then be transported to Oxford by road in a twice-daily service.
Some items will be scanned and sent to students' computers electronically.
It is estimated there will be 200,000 requests for items each year.
Librarian Dr Sarah Thomas said it was important to preserve all the books so that future generations could have access to the recorded knowledge of the past.
"The BSF will prove a long-awaited solution to the space problem that has long challenged the Bodleian," said Dr Thomas.
"We have been running out of space since the 1970s and the situation has become increasingly desperate in the last few years."
Oxford University's Vice Chancellor Professor Andrew Hamilton said: "The importance of the Bodleian Libraries and their extraordinary collections cannot be overestimated."