Members of Library of Birmingham staff, council representatives and Carillion employees gathered in the dramatic rotunda which will house the five-storey book wall.
The rotunda, at the very heart of the library, features a series of cantilevered circular balconies each providing access to a different part of the shelves that comprise the book wall.
Escalators zigzag across the space, providing stunning views throughout the library and access for all to over 400,000 books, more than double the amount currently on show at Central Library.
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Dozens of people have marched through Lincoln, in protest over plans to close the city's only NHS Walk in Centre.