Akkaya Travertines Akkaya Travertines, situated 10 kilometers southwest of Bolu on the Mudurnu road, is often referred to as "Pamukkale of Bolu" due to its breathtaking scenery. Akkaya Travertines is one of the few remaining natural environments in Bolu and the Western Black Sea Region that has remained untouched. The water in the region is rich in calcium and is about 20 degrees Celsius. When water flows from the terraced surfaces, carbon gas is released, resulting in the volatilization of lime and the formation of limestone deposits. The highlight of this park is the travertine pools of mineral water, which have a mild taste. Visitors can swim in the natural rock pool or quench their thirst by drinking the refreshing water from the fountain.