The geomorphological natural monument is located in the Parnidis Landscape Reserve, in the southern part of Parnidis Bay. At this point, the Parnidis dune (its enormous mass of sand) presses against the shore of the lagoon. On the surface of the ground lies a dark gray carbonated sludge pressed from the bottom of the lagoon - Mergelis of the lagoon. The area of ​​the exposed lagoon Mergelis by the Parnidis dune along the Curonian Lagoon extends for about 150 m. There are two approximately parallel sections of the lagoon Mergelis in this area. The height of the first Mergelis, which is located right next to the Parnidis dune slope, is up to 1-3.42 m and its width is up to 12 m. The second stretch of the lagoon Mergelis stretched away from the Parnidis dune. Both sections are separated by water, concentrated in an elongated and somewhere up to 8-9 m wide basin. The second section is lower - up to 1 m high, narrower - up to 8 m wide. From the side of the Curonian Lagoon, its slope is being constantly washed away and destroyed by the waves of the lagoon. The age of the Lagoon Mergelis is about 5,000 years. Most of the surface of the Lagoon Mergelis is overgrown with grass: pigeons, nettles, etc. The condition of the lagoon depends very much on how fast the slope of the Parnidis dune moves on it, how fast new places of the Mergelis erupt from the bottom of the Curonian Lagoon, the extent to which they are destroyed by the waves of the Curonian Lagoon and the annual frost. In the past, the inhabitants of Nida used Mergelis to improve the soil in their gardens (as a natural fertilizer).