Potential toxic element accumulation in soils and plants is one of the leading environmental problems in recent years. In many countries, mining enterprises are generally abandoned for reasons such as increasing costs, depleted reserves, and changes in ore quality. The negative effects on the environment during or as a result of these activities are known. The focus is on investigating the Hg concentration accumulated in the soil and plants around the abandoned mercury quarry located in the north-west Black Sea region (Tezcan Hg Mine). While the distribution of Hg and As is observed toward the downward slope in the mining area, it has been observed that it decreases as it moves away from the source area. The relationship of Hg concentration with granite intrusions in the areas of upward slope and topographic barriers is due to the alteration of the hydrothermal phase mineralizations and the accumulation of ore rocks. According to the Geoaccumulation Index in the lands around the abandoned mercury quarry in the Northwest Black Sea region, AsIgeo and HgIgeo accumulation are found as extremely; according to contamination factor, CFAs and CFHg values are found as very high; according to enrichment factor, EFAs and EFHg are found as extremely high; according to the Potential Ecological Risk Factor, As and Hg are found as very risky, and according to the Pollution Load Index, they are found as Pollution. As well as in soils, As and Hg concentrations were determined in Mentha longifolia (L.) L. subsp. typhoides (Briq.) Harley (dere nanesi) from the Lamiaceae (Turkish name: Ballıbabagiller) family, Taraxacum buttleri Van Soest (karahindiba) from the Asteraceae (Turkish name: Papatyagiller) family, Plantago lanceolata L. (damarlıca) from Plantaginaceae (Turkish name: Sinirotugiller) family, and Pyracantha coccinea M. Roem. (ateşdikeni) from the Rosaceae (Turkish name: Gülgiller) family, which were collected from the same locations. According to 207Pb/206Pb—208Pb/206Pb, the origin of lead in the soils within the enterprise is of geogenic origin, and according to the results of 87Sr/86Sr—143Nd/144Nd, it is thought that the samples examined are caused by granitoid.