Crystilan is one of the most well-known Thassilonian ruins in all of Varisia. Located on Peridot Isle in the Steaming Sea, it is an entire ancient city, perfectly preserved within a crystal dome. The crystal sparkles in the sunlight, making it easily visible for miles. Scholars have long traveled there to study what can be gleaned of Thassilonian culture and copy the writing found on its many buildings. Efforts to dig through the crystal or magically transport into the city have been wholly unsuccessful, and excavation has even shown that the crystal dome might in fact be a perfect sphere.
- Rob Lazzaretti. (2011). Inner Sea Poster Map Folio, p. 1. Paizo Publishing, LLC.
- James L. Sutter. (2007). Varisia. The Hook Mountain Massacre, p. 63. Paizo Publishing, LLC. ISBN 978-1-60125-038-4
- Adam Daigle and James L. Sutter. (2012). Rise of the Runelords Anniversary Edition Player's Guide, p. 7. Paizo Publishing, LLC.