Illustration done by =jcbarquet. I've currently commissioned him to give some rough environmental sketches of the different far off regions in my 'Expanded' universe for My Little Pony/Equestria.
The greatest repository of knowledge in the world of Equestria, Machu Alpacchu (based on Machu Picchu in South America) is the home of the llama-folks of Equestria. Living high in the mountains, these friendly residents are tasked with collecting as much knowledge and lore in Equestria and returning them to the 'Stone Library'. The llamas are particular devoted to 'The Stone' (based on the Mayan Calendar stone) and it shows in both their architecture and lives.
In addition, the city has been targetted by a number of 'baddies' in the past, but the appearance of the city is always brief - then followed shortly by a lengthy vanishing act. When the city disappears, it does not reappear until the end of a Mayan Long Count (which would be every 394 years). Because of this, the city's existence has fallen into tales of both myths and legends (though Princess Celestia always makes at least one trip to the city every Long Count).