Gilius is one of the four larger lakes surrounding the city of Tytuvėnai, distinguished by its special colour and great diversity of flora and fauna. The area of the lake is 36 ha, and the deepest point reaches as much as 23.1 m. Legend has it that the lake flew in with a tornado and fell down on the forest that grew here. The emerald green of the water comes from the springs that feed the lake. Their water is saturated with dissolved carbonates that come from the depths of the earth. The green colour of the water is accentuated by the reflection of the lake environment in the water and the green weeds growing in its depths. The lake was formed 10 – 14 thousand years ago as the glaciers melted.

At the current location of the lake, a massive block of ice stood, which, over time got covered up with soil and finally melted when the climate warmed up completely. The water from the melted glacier remained in the ravine formed by it. You will be able to learn about the natural treasures of the lake by traveling along the 3.3 km long educational trail that leads along the constantly changing shore of the lake.