The library of the National Palace of Mafra looks like the kind of library where something magical

could happen at any given moment.

Think long hallways, bookshelves lining the walls all the way up to these arched ceilings.

It's an old library that's part of an old palace built in the 1700s.

And its books are even older.

There are more than 35,000 volumes here, including what's considered the first encyclopedia,

a whole collection of books that were forbidden during the inquisition, and even in Canabula,

books that were printed before the 16th century.

The collections here are extraordinarily rare, but the books aren't the only unusual things

about this library.

At the end of the day, the lights are turned off, the building closes, and out come the

winged librarians of the night.

I'm Abby Peralt, and this is Atlas Obscura, a daily celebration of the world's strange,

incredible, and wondrous places.

Today, we're heading to Mafra, Portugal, about 25 miles northwest of Lisbon, where we'll

meet the librarian who looks after these books by day, and the bats that do so by night, after this.

For me, the library is the old, together, the books.

I have one that I love, it's about cartography, it's from 16th century.

That's Teresa Amaral, she's a librarian at the National Palace of Mafra.

I have lots of things to do, because it's not a normal library.

It's definitely not a normal library.

It's a historical library, and maybe one of the most important in Western Europe.

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