Uncontrolled municipal/urban solid waste (MSW) disposal has been a problem for many decades in the Mediterranean region and has had an environmental/ecological impact. In particular, MSW dumped illegally in forests and woodlands can cause severe forest fires. In the present research, uncontrolled waste disposal areas were recorded. These areas include forest areas which subject to the responsibility of the Forest Service of Megara, Greece. The SW Maps geographic information system (GIS) mapping application was used on sites to collect geographical information data and photographic material. The aim was to minimize the environmental degradation caused by uncontrolled waste disposal and its impact on the regions. 38 uncontrolled waste disposal sites were identified, occupying a total area of 41,313,650 m2. The waste volume amounted to 1421 m3, with the waste mainly being composed of plastics, glass rags, textile, paper, cardboard, garden and agriculture–forestry waste, and construction and demolition waste. The sites were mainly located in mountainous and semi-mountainous areas with road access. A significant percentage (26%) of them were recorded as being near or in streams, so waste could be carried away upon heavy rainfall and contribute to flooding. Moreover, these places are characterized by high slopes that can enable waste to move to a larger area with apparent negative effects. Finally, an environmental remediation study was prepared in accordance with current national regulations and modern scientific and technical concepts. Proposals for a potential solution to this environmental concern and rehabilitation costs are provided to help society and decision makers to integrate relevant activities and strategies towards enhancing sustainable development.