Philippe Braquenier is obsessed with all the ways humanity preserves information. Not just libraries and data centers, but weird stuff too, like Reyers Bridge in Belgium that housed its blueprints inside the bridge's pillars and the Bahnhof company in Sweden that's decorated like a space station.

He's spent the past four years traveling around Europe and beyond shooting the photos in Palimpsest, the ongoing series he calls the work of a lifetime. Let others ponder the rich stores of knowledge within these places; Braquenier is fascinated by the spaces storing it. "The preservation of knowledge is the cornerstone of evolution,” Braquenier says. “If you lose any kind of important information, you are doomed to try to recover it.”

The idea came to him as he read a scientific paper explaining how digital devices can lose information. He fell down an internet rabbit hole of research that led, in May, 2012, to the Royal Library of Belgium and its 6 million books on 93 miles of shelves. He has since followed his muse to no end of interesting places, like the Swiss Federal Office of Metrology and its copy of the international prototype of the kilogram, the only base unit still defined by a physical object. “The whole building is created so that it doesn’t have any systemic shock,” he says. “Walking was really strange—there’s no movement, it’s like a spongy floor.”

Of the 31 places Braquenier has visited so far, CERN remains his favorite. He got to see the Large Hadron Collider, which produces 30 petabytes of data annually. “I was intrigued by how they are preserving knowledge,” he says. “The Hadron Collider makes so much data in one experiment, they have to process it for months.” The enormous whirring data center makes such a racket he had to wear ear protection.

Braquenier found analog data centers like libraries and the Mundaneum---a repository of 12 million index cards meant to catalog the world's information---welcoming. Their digital counterparts weren't always so accommodating. No one would let him inside Google's data center in Boudour, Belgium, so he photographed the chain-link fence outside. Security guards still jotted down his license plate number.

The photographer is no less fanatical about preserving his own data. He stashes copies of his prints in a dark, dry drawer in his office and keeps backups of everything on two hard drives. Just in case.

Text by Charley Locke for Wired