In the area surrounding Lake Marathon, we can observe the presence of significant natural ecosystems. Rich forests, mainly a wood of pines, are located around the lake and are currently under a process of natural recovery after their destruction due to extensive wildfires, the most recent one having taken place in August 2017. In addition, we can also observe the rare and protected species of Fritillaria obliqua, which earned its name from the shape of its blossoms. Lake Marathon is also the only place in Attica where otters appear, a rare and endangered species of mammals. We are also informed by various testimonies, that the Lake has always been rich in endemic species of fish as it is said that “once upon a time the abundance of fish in the Lake was such that the surplus was burned". Finally, let’s note that the area of ​​the Marathon is also endemic to another species of fish, the so-called Attic fish. In the 1930s, in an effort to combat malaria, the authorities used a certain type of fish in the lake to eat the eggs of the mosquitoes.