It is one of the oldest areas in Latvia and one of the richest ones in terms of biological diversity. The evidence of geological history of the Baltic Sea can be observed here: The ancient slope of the Baltic Ice Lake (30-50 m high) or Slītere Blue mountains and the unique kangari-vigas terrain complex.

Kangari-vigas terrain complex consists of dune hills (kangari) that alternate with narrow swampy valleys (vigas) that stretch for kilometres. Nowadays, no terrain complexes of a similar nature in the same area occur worldwide. A path through the vigas of Lake Pēterezers has been created, which allows one to enjoy the ups and downs of the kangari-vigas terrain complex.

The deciduous forests growing on the slope of the ancient bank of the lake have been unaffected by the economic activity of man and the unique and moist micro-climate of the forests and bogs at the foot of the slope provides asylum to a high variety of plant and animal species, therefore researchers figuratively call this forest - Northern Rainforest.

All forest types characteristic of Latvian nature are represented in the forest, as well as one half of plant species and 60% of moss species growing in Latvia. The diversity of biomes or habitats has created pre-requisites for the huge diversity of invertebrates: one half of the total number of rare beetle species, two thirds of rare snail species and one third of rare butterfly species included on the lists of rare and protected invertebrates of Latvia reside here.

The coastal areas of the sea are places of bird concentration. Bird migration route crosses Cape Kolka, where the Baltic Sea and the Gulf of Riga meet. And, during bird migration season, the cape can be crossed by tens of thousands of birds per hour! Meanwhile, a couple of kilometres further into the mainland, in Baži bog, the largest mating site of black grouse in Europe – 66 grouse cocks was registered in 2010!

Four improved nature trails have been developed at the national park, several bicycle routes have been marked in the terrain, car parking areas have been built near the sea and further away on the mainland. The coast of the Baltic Sea presents the visitor with a tens of kilometres long white sand beach and dunes that protect ancient coastal fishermen villages from natural disaster. The sites of the park that are most popular among the visitors are Cape Kolka and the sea coast, as well as the Slītere Lighthouse complex.

Slītere National Park is one of the oldest natural areas in Latvia. The nucleus of the park was established in 1923 (in the area of 1,100 ha), which was initially called Slītere Nature Monument. By 1999, the area was known as Slītere State Natural Reserve, but in 2000 it was renamed Slītere National Park.

The coast of the Baltic Sea has been inhabited for several centuries. Ancient Liv fishing villages – Sīkrags, Mazirbe, Košrags, Pitrags, Saunags, Vaide, Kolka and Uši have been situated here for centuries. Livs are one of the seven Finnish tribes of the Baltic states, which flourished from the 10th to 13th century. Active economic activity at Liv villages was conducted before the Second World War, but then their development was ceased by the border area, which was closed during the Soviet period.

Nowadays, Liv culture, being a significant part of the cultural heritage of the Northern Europe, is still alive here. And some fisheries are still involved in fishing at the small fishing villages. The activity is higher in the summer season, when cottagers and visitors arrive to enjoy the primeval nature, wide, white beaches and silence of Slītere National Park.

Natural development processes of ecosystems are in progress in the nature reserve area of the national park. The trees that were broken during the large storms of 1960 in the area of approximately 100 ha were not removed, and the restoration of the forest occurs naturally. Meanwhile, at Baži bog, the development course of ecosystems has been ensured since the fire in 1992 – the burnt trees were left and natural restoration of the forest and the bog is in progress.

The overall area of natural grasslands in the park is not high, however, these grasslands are important on the national level. The evidence of ancient methods of economic activity can still be perceived in the old pastures and meadows – Dāvida, Tamnītes and Zvejnieku meadows. They are very important for biological diversity, as well as are a cultural and historical heritage object.