Lake Kozjak: The Largest Lake at Plitvice

Lake Kozjak is the heart of Plitvice Lakes National Park — the largest body of water, the geographical dividing point between the Upper and Lower lake systems, and the only lake that visitors cross by boat rather than on foot. The boat journey across Kozjak is brief, but it is one of the park’s most distinctive experiences: silent, slow, surrounded by forested limestone cliffs, and offering perspectives on the lake’s scale that no boardwalk can provide.

Key Facts

The Electric Boat Crossing

The boat across Kozjak is an open-sided electric vessel — silent and emission-free. It crosses on two routes: P1 to P2 (a shorter crossing at the northern end of the lake), and P2 to P3 (the main crossing linking the Upper and Lower Lakes sections, approximately 10–15 minutes). Both are included in the park ticket at no additional cost.

The crossing is genuinely beautiful. From the water, the scale of the lake and the height of the forested limestone cliffs on either bank are apparent in a way that the boardwalks cannot convey. The water is extraordinarily clear — visibility to several metres — and the electric motor produces no noise except the gentle movement of water. In summer, fish are visible below the surface throughout the crossing.

In peak season, there can be a wait of 20–30 minutes at the P3 terminal for the boat. The P2 terminal (coming from the Upper Lakes) is typically less congested. If you are following Route C (Entrance 1, Lower Lakes first), you will use the P3 terminal and may experience a queue in peak season. Route H (Entrance 2, Upper Lakes first) approaches via P2, which tends to be faster.

What You See on the Water

The view from the boat across Kozjak is one of the park’s most meditative moments. The forested cliffs rise steeply on both sides; the water changes colour from bright turquoise near the shores to deep blue in the centre. Stephanie’s Island — a small travertine formation near the centre of the lake named after Crown Princess Stéphanie of Belgium, who visited in 1888 — is visible from the boat. Herons and other water birds are frequently spotted on the lake edges. In calm autumn mornings, the reflections of the surrounding forest in the flat lake surface are extraordinary.

Lake Kozjak in Different Seasons

Spring: The lake is full from winter snowmelt; waterfalls feeding it are at maximum volume. The blue-green colour is vivid. Morning light on the western cliffs is particularly beautiful.

Summer: The lake is warm and the colour most saturated in direct sunlight. Boat queues are longest in July and August — factor in 20–30 minutes of waiting time when planning your route.

Autumn: The beech forests surrounding the lake turn gold and red in October. The reflections of autumn colour in Kozjak’s surface are among the park’s finest photography subjects.

Winter: The lake does not freeze completely due to its depth, but ice forms along the shallow edges. The boat typically continues operating in winter, though on a reduced schedule. Confirm before visiting: +385 53 751 014.