The investigation of hydrogeochemical evolution of hot springs through water-rock interaction identifies flow pathways, dissolution, ion exchange, and water quality. This study examines the chemistry of hot and cold karstic springs in the Allah Akbar heights of Dargaz to determine their origin and geochemical evolution. Rock samples from the Tirgan Formation and travertines were collected, and thin sections were studied for facies and diagenetic history. In two seasons (2023), ten water samples were taken from the springs, and parameters (T, pH, EC, Eh, TDS, DO) and major ions were measured. Thin sections revealed a dual-porosity system in the Tirgan Formation, which, by increasing water-rock contact, played a direct role in enriching water with Ca²⁺ and HCO₃⁻ and forming travertine around hot springs. Quaternary travertines along active faults indicate the continuation of these processes. Cold spring temperatures ranged 15.6–19.4°C, hot springs up to 32.2°C, and EC between 256–1022 µS/cm. Data were processed using Piper, Gibbs, Schoeller, Wilcox, SI, and Eh-pH diagrams. Results show that hot spring evolution results from lithology (Tirgan Formation), diagenesis (dissolution and dual porosity), and tectonics. Hot springs are of Ca-HCO₃ type with a common origin, while Chelmir is of sulfate type. According to Gibbs, carbonate weathering is the main factor controlling water chemistry, and SI confirms supersaturation with respect to calcite and dolomite. Most springs have "good to acceptable" drinking water quality and fall into class C3-S1 for irrigation. This study clarifies the role of diagenesis and dual porosity in the evolution of the Tirgan aquifer and reveals the geotourism potential of the hot springs.