The accumulation Komarnik Lake is located approximately 2 kilometres west of Lenart in Slovenske gorice. It encompasses  26 hectares and has an average depth of 1.5 metres. To the east of the lake lies the Črni les forest, to the southeast grasslands and intensely cultivated fields. After the Pesnica river had its stream regulated and the area of the Pesnica valley was ameliorated, the lake with its immediate surroundings became the last haven and important habitat for some animal species and the sole habitat for many rare and endangered plant and animal species. Aquatic birds in particular are highly diverse, as for them the lake represents one of the most important nesting sites in Slovenia. Otters also call the area around Komarnik Lake and its surrounding streams and ponds home. A pathway with information panels surrounds the lake, along with two bird-watching posts. The lake can be accessed in two ways: either by parking at old people's home St. Agata  or by parking underneath Hrastovec castle.