Karstic environments are characterized as areas of intense rock dissolution, which allows the generation of several typical features, such as sinkholes, resurgences, caves, and dolines. The spatial distribution of these features is of great importance to identify the contamination vulnerability of karst aquifers and serve as a basis for the application of assessment methods. This study aimed to identify and classify the areas vulnerable to underground contamination in the karstic region of the Terra Ronca State Park (PETeR) and its surroundings. The method chosen was the COP, which assesses the physical conditions of the environment (relief, lithology, soils, precipitation, karst features, and vegetation) to determine the areas naturally vulnerable to contamination. The analyses were performed in a GIS environment. The results indicated five categories of areas vulnerable to groundwater contamination: Very High to High (3.14%), Moderate (16.21%), and Low to Very Low (80.62%). The Terra Ronca State Park was the analysis unit with the highest vulnerability in the region (9.91%), due to the concentration of karstic features in the area. The acquired results aim to help in the underground water resources conservation as well as the speleological patrimony.