The main objectives of this paper are to present the impact of former iron ore mining on the transformation of the soil cover and to demonstrate how these changes have affected plant cover. The research was carried out in 2012-2015 on the remnants of a former iron ore mining (gob piles) located in the northern foreland of the Świętokrzyskie Mountains. On two former post-mining fields eight soil profiles (four on the gob piles and four on untransformed areas) and eight phytosociological relevés were made using the Braun-Blanquet method. Physicochemical analyses were made of all the collected soil samples. The gob piles have favourable physico-chemical properties, differing from the properties of the poorer soils of the untransformed areas. Preferred chemical properties of the gob piles, including increased pH values and increased content of assimilated elements (Ca, Mg, K, Na) also affect the increase in the quality of fossil soil horizons. Former iron ore mining has led to significant, positive changes in the soil cover of the researched areas. The clayey-silty gob piles there have become fertile habitat islands among oligotrophic, sandy, untransformed soils, and the effect of these changes is an increase in the number of plant species.