Abstract: The Otlukbeli Travertines, located in the Otlukbeli district of Erzincan Province in Eastern Anatolia,constitute one of the most distinctive and geologically rare travertine formations in Türkiye. These travertinesare terrestrial carbonates with distinct geomorphological features, formed by Fe-oxide-rich mineralized watersemerging along fractures and faults under the influence of active tectonics in the region. In the study area, theseterrestrial carbonate deposits are observed as travertine cones, ridge-type travertines, and slope travertines. While inactive travertine ridges and cones are widely observed in the field, there are also ongoing deposits of activecarbonate precipitates.In this study, approximately 60 travertine cones and 15 travertine ridges were described in detail. The measuredtravertine cones and ridges were evaluated within a geographic information system, and the geomorphological andgeological characteristics of the travertines were mapped at high resolution. From a sedimentological perspective, thisstudy presents, for the first time, the depositional systems and lithotypes of these terrestrial carbonates. Accordingly,laminated, crystalline crust, gas bubbles and paper-thin rafts are the mainly lithotypes observed within these threedifferent travertine systems. Travertine pools and terracettes are commonly observed on the slope travertine.Petrographic analyses also revealed trace amounts of Fe-oxide/oxyhydroxide minerals in these travertines.The Otlukbeli Travertines are geological formations of considerable importance in terms of geological andcultural heritage criteria. Their rarity, scientific research potential, and value for education and geotourism make theOtlukbeli Travertines an important geosite that requires protection. The preservation of these unique occurrences,the promotion of scientific studies, and their evaluation within the scope of sustainable geotourism are essential.