This is an art installation by the Swedish artist Susanna Hesselberg, called When My Father Died It Was Like a Whole Library Had Burned Down.
My Modern Met’s blog describes it as “a library that plunges into an infinite abyss. Visible only from above ground, the intriguing installation is inconspicuously marked and, from a distance, looks as though it’s just a square frame laying on the grass. As viewers approach it, however, they can easily see the stacks of books descending into the earth. Its compact structure is reminiscent of a mining shaft or water well with no apparent bottom.” – http://www.mymodernmet.com/profiles/blogs/susanna-hesselberg-descending-underground-library