Aidu/Ojamaa is located in the Ida-Viru County, on the edge of big forests. The unique 34 km2 hiking area is a mine with renewable nature. The area is unique because it offers possibilities to go for a hike on water, in the desert, or to the mountains. In the recovered quarries, long blue fjords run between the mountains which resemble polar landscapes. The water there is so clear that trees that started growing there before the flood can be seen at a depth of 20–30 m. The water at Aidu has a unique light blue colour (however, its pH level is natural).