Ice Lake and the Yoldia Sea. The effect of the bedrock on the traditional Espoo natural landscape was significant; high and steep cliffs stand up from shallowly waving fields. The oblong lakes in northern Espoo are located in valleys in the bedrock. The formation of the bedrock has determined the shapes of the coastline, such as Espoonlahti and Laajalahti. Because of upthrust, paludification of forests and overgrowth of lakes, bogs and layers of peat have formed on top of the clay at some places. Sea area The sea area of Espoo is a considerably narrow strip between the sea areas of Helsinki and Kirkkonummi. The depth of the southern part of the sea area, in the outer archipelago, is a few dozen metres at the most. The ship route between Helsinki and Stockholm, Sweden goes through the outermost parts of the sea area which contains small treeless, sea-washed islets. One of them is the former fortification island of Kytö. The smallest islands are shallow islets, such as Stenskär. They are significant nesting grounds for birds and many of them are nature-protected areas. In summertime there might be flowering meadow patches on the islands. The islands closest to the Espoo shoreline include Stora Herrö, Pentala, Kopplorna and Lehtisaaret. The islands host many vacation buildings, and they are often referred to as an intermediary archipelago. The islands in the inner archipelago are larger and lusher and contain boat harbours and buildings, as well as permanent settlements on the islands closest to the shore. There is a land connection from the mainland to the inhabited islands in Suvisaaristo and it forms a district of its own, with a more rural image than most of Espoo. The sea area extends inland at many places as bays, of which the largest are Espoonlahti in the west and Laajalahti in the east. Bays on the shoreline between them include Nuottalahti, Haukilahti and Otsolahti. The bays are shallow and contain many islands, particularly in Espoonlahti. Most of the islands in Laajalahti are located across the municipal border in Helsinki. The largest peninsula in Espoo is Soukka, fracturing into an archipelago in the south. Thus the peninsula hardly offers any views to the open sea. The nearest ship harbours are located in Helsinki, while the Espoo shoreline contains many small boat harbours, the largest being the boat harbour in Suomenoja. The maritime traffic in front of Espoo mainly