The characteristics and potential for carbon dioxide capture and storage of the fifteenth-century lime mortar samples from City Palace, Udaipur, India, were studied. Physiochemical analysis followed by XRD, FTIR, TGA-DSC, and FE-SEM was performed. The findings demonstrate that calcium-rich eminently hydraulic mortars were used with a binder/aggregate (B/Ag) ratio of about 1:2.8±0.42. Mineralogy identified load-bearing phases: aragonite, vaterite, and calcite with 45±5% clay minerals. Absorption and stretching bands detected by FTIR at 1631 cm⁻¹ and 2954 cm⁻¹ corroborate the inclusion of plant organics. All samples showed aragonite around 870 cm⁻¹, which can be traced back to bonded CO₂ and the subsequent carbonation throughout the age of the structure. TGA-DSC validated XRD and FE-SEM analysis exhibited 18.66±3.40% weight loss at >600 °C, indicating calcite decomposition and CO₂ release with CO₂/H₂O ratio of 3.31 to 3.66. From the historic example, a debate has been sparked about using lime mortars in contemporary construction to mitigate the carbon footprint with inherent attributes.