Lokvarka Cave, Limestone cave in Lokve, Croatia.

Lokvarka Cave is a limestone cave system in Lokve with six distinct levels, of which four are accessible to visitors through illuminated pathways and stairs. The underground formation includes several chambers carved naturally by water and geological processes over thousands of years.

Jakov Bolf, a merchant from Lokve, found the cave in 1911 while quarrying limestone for lime kilns. In 1912 the entrance was widened and three staircases and a bridge were installed, opening it to visitors. That same year Josip Poljak published the first article on the cave, with a plan and the earliest known photographs taken deep inside a Croatian cave. It was declared a geomorphological natural monument in 1961.

The Department for Nature Protection in Zagreb designated Lokvarka Cave as a protected geomorphological natural monument in 1961, preserving its geological formations.

The cave entrance lies about 2 km east of Lokve centre, just off the Zagreb–Rijeka motorway, on the southeastern slopes of Kameni vrh at 760 m. Only the first four of six levels are open to visitors, and the tourist route drops about 75 m from the entrance. Temperatures in the cave stay between 7.6 and 8.2 °C with 100% humidity, so bring sturdy shoes and a jacket.

In winter, when the cave is normally closed, ice stalagmites form near the entrance in club, egg, column and mushroom shapes, sometimes with wavy surface relief. The first specimen of the endemic beetle Croatodirus ozimeci was found in the Virgin Level in 1996 and described in 2004; it is known only from this cave.