For over 2,000 years, the precise location of the Stone Tower—the midpoint of the ancient Silk Road, where caravans traveling between Europe and Asia paused to rest, trade, and resupply—has remained a mystery. Claudius Ptolemy (AD 90–168), an Alexandrian, was an astronomer and geographer. In his third work Geographia, he described the Stone Tower, a special place high up in the mountains in a region referred to as the Roof of the World, which marked the mid-point on a complex network of overland routes collectively known today as the Silk Road. Scholars have long debated its location, but no work until now has focused solely on identifying this elusive site.

This book explores the search for the Stone Tower and its significance in ancient geography, cartography, and trade. Determining its location not only resolves a historical puzzle but could also lead to the discovery of other lost settlements described in Ptolemy’s Geographia. The book is divided into three sections: the origins of the Silk Road, the historical forces that led to the tower’s prominence, and the precise identification of its location.

The author demonstrates why Ptolemy’s text alone is insufficient to pinpoint the site and introduces four key criteria that the location would have logically needed to satisfy for it to have become such a prominent meeting place and caravanserai. He argues that the Stone Tower corresponds to the Sulaiman-Too in Kyrgyzstan, the holiest mountain in Central Asia. This site was a key meeting point for traders and holds significant spiritual and cultural importance, with connections to Zoroastrianism and the Sasanian Empire.

By solving this ancient riddle, the book sheds new light on Silk Road history, offering fresh perspectives on trade, geography, and the civilizations that shaped this vital network of commerce and cultural exchange.