Vilnius City Municipality, partly Vilnius District
Vilnius
nature trail around a protected chain of lakes
Žaliųjų Ežerų g. (Balsio ežeras), Verkių regioninis parkas, Vilnius
54.79250, 25.32860
2-4 hours for the roughly 10 km loop around Balsys
late spring and summer; lady's slipper orchids bloom in late May-June, swimming is best June-August
Green Lakes, Lake Balsys, Kryžiokai Lake, Balsys
Why the Green Lakes trail is worth visiting
The Green Lakes are a chain of lakes on the northern edge of Vilnius in Verkiai Regional Park. The main focus is Lake Balsys, encircled by a roughly 10 km walking and cycling loop along steep forested slopes. It is one of the easiest places to reach wild-feeling nature inside the city.
The site is known for its unusual water colour: the lakes look green, almost emerald. The relief adds to the effect: the banks are steep, wooded, and in places rise about 40 m above the water. Wooden stairs and boardwalks help on harder sections, and the Balsys viewpoint stands on one of the slopes.
It is important to know that there is no single officially marked Green Lakes Nature Trail route. The name usually refers to the popular established loop around Balsys. The marked educational routes of the park directorate are the Verkiai Route and the Old Villages Trail, each 10 km, and the lake loop can be combined with them.
Why the lake water is green
The greenish colour is caused not by algae but by a high concentration of carbonates, calcium carbonate, in the springs and groundwater that feed the lakes. This is stated by VLE and protected-area information; the lakes are richly supplied by underwater springs.
The same carbonates settle on the lakebed as freshwater limestone, so the green colour and limestone layers are two results of the same phenomenon. The colour is most vivid on a sunny day, which is the best time to plan a visit.
Balsys and the chain lakes: depth, slopes, origin
Lake Balsys, also called Kryžiokai Lake, is the largest and deepest lake in the chain. VLE gives its area as about 55 ha and its maximum depth as 38.8 m, making it one of the deepest lakes around Vilnius. The shores are steep and forested, rising about 40 m above the water and descending almost as much below it.
VLE classifies the Green Lakes as tunnel-valley lakes: long, narrow, steep-sided basins carved about 18,000 years ago by meltwater flowing beneath a glacier. The chain consists of six lakes, including Balsys, Gulbinas, Mažasis Gulbinas, and several smaller lakes. Notably, Mažasis Gulbinas lies about 20 m higher than Balsys.
Protected area: Green Lakes Landscape Reserve
The lakes and their surroundings form the Green Lakes Landscape Reserve, which VLE calls one of the most valuable landscape complexes of Verkiai Regional Park. It protects deep lake basins, rare plant habitats, and mature mixed forests.
One of the most important natural values is the population of the lady's slipper orchid, Cypripedium calceolus, considered one of the largest in Europe. This is a Red Data Book plant, so visitors must stay on paths, avoid picking flowers, and not trample slope vegetation.
Verkiai Regional Park was established in 1992 and is one of Lithuania's smallest regional parks, about 2,529 ha according to protected-area data. Its northern part is natural, with the Green Lakes, while its southern part is cultural, with Verkiai Manor and the Calvaries. The park is managed by the Pavilniai and Verkiai Regional Parks Directorate.
Trail, viewpoint, and other park routes
The loop around Balsys follows steep forest slopes, so wooden stairs and boardwalks are installed in more difficult places. Climbing to the eastern or southeastern bank brings you to the Balsys viewpoint, with a panorama of the lake and forest. The full loop usually takes 2-4 hours.
The park has more than 30 km of educational trails in total. In addition to the Balsys loop, there is the Verkiai Route, 10 km from Verkiai Manor, the Old Villages Trail, 10 km, and the Calvary Way of the Cross, 7 km. Part of the area can be reached by bicycle; an asphalt cycle path runs from Santariškės to the park.
On the southern shore of Balsys there is a beach, boat and pedal-boat rental, and a recreation facility. In summer it is a popular swimming area, so it is worth arriving early.
How to visit and what to combine
The lakes, beaches, and trails are a public, free nature and recreation area; no general ticket is needed. Only services provided by the directorate, such as guided tours, are paid, and their prices and hours should be checked on the official park directorate page.
The best time to visit is from late spring to the end of summer: the water colour is strongest, lady's slipper orchids bloom, and swimming is possible. The visit is easy to combine with the cultural part of the park, Verkiai Manor and Vilnius Calvary; in summer, check water-quality notices before swimming.
