At Lavrion pilot site, in situ Nature-based and Eco-friendly solutions for mines and mining waste (i.e., phtytoremediation-phytoextraction technologies and bioleaching) will be implemented and tested, focusing on mining and metallurgical waste deposited in specific areas within or at the borders of the urban tissue. Metals such As, Pb, Cd, Cu, Zn, Fe, Mn are present in very high concentrations in waste piles and are mainly in form of sulfides and oxides. Both soil remediation and the possibility of creating an added economical value (by recovering metals) will be evaluated. The proposed site is ideal for testing Phytoremediation Solution and concurrent Metal Phytomining using Trees (LAMMC) for the Recovery of Critical Metals from Mine Waste. The recovery of heavy metals from soils/deposits by specific trees will be demonstrated, together with the immobilization of heavy metals (and especially) arsenic by soil amendments (utilizing basic iron sulfates). The success of immobilization will be approved using column experiments, while suggestions will be made for further utilization of the biomass (rich in metals) based on specific tests (chemical and mineralogical analyses, bioavailability fractions, etc.). Finally, the environmental and social impacts regarding the implementation of the selected method(s)/technologies(s) will be targeted, focusing on the after-mining era and the relevant stakeholders’ engagement.