Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
With the Dark Tower of Sauron, the capital of Gondor and many more, J. R. R. Tolkien’s Middle-earth is full of fortified citadels and imposing fortresses. Hundreds of years ago, a region in the central Himalayas might have resembled Tolkien’s fictional realm.