More than ten thousand years ago the first parts of Saaremaa arose from the Baltic Ice Dam Lake. The uplift of the earth's crust is continuing even today - 2mm per year. The West - Estonian islands are lowlying plains resting on limestone, their average elevation being about 15 meters above sea level. Limestone has become denuded in a great number of places, resulting in cliffs, limestone pits and quarries at Mustjala, Ninase, Pulli, Uugu and Kaugatuma.

Because of its mild maritime climate and a variety of soils, Saaremaa has a rich flora, illustrated by the fact that 80% of the plant species found in Estonia are represented here. Altogether 1200 species of vascular plants can be found in Saaremaa. About 120 of the local plant species are rare ones which have received special protection status.

The most famous endemic species is Rhinanthus osiliensis - a rare little flower growing mostly in spring fens. Orchids, rare and beautiful flowers are widespread: out of the 36 species found in Estonia, 35 of them are found on Saaremaa and neighbouring islands.

Over 40% of Saaremaa is covered with forests. They are mostly mixed forests but in some areas one can also find broad - leaved (deciduous), which are relict plant communities of former milder climatic periods. Wooded meadows were still common in Saaremaa before World War II, but many of these unique natural complexes have gradually become overgrown and thus turned into the ordinary forest.

The same is true for alvars (limestone areas covered with thin soil and stunted vegetation). Once a typical and exclusive landscape element in Saaremaa alvars are now in decline. Nature conservation planning for Saaremaa now includes protection of the largest and most unique alvar areas.

Saaremaa has a wide variety of rare wildlife species - ranging from insects to seals. The smallest protected wildlife species include Cloude Apolle butterflies and Roman snails.
The coastal areas of Saaremaa are famous seal habitats. The gray seal which is common here can be found in three large permanent resting areas on the islets off the coast in the western and southern parts of Saaremaa. The local population of grey seal is slightly increasing Ringed seals can also be encountered everywhere in the coastal waters of Saaremaa, but because of their timidity it has not been possible to make an estimation of their number.

Our islands lie within the East - Atlantic flyway, which is the migration path of waterfowl. This "bird - road" connects North - eastern Europe with arctic regions and each year hundreds of thousands of migratory birds visit Saaremaa in spring and autumn. The barnacle goose, mute swan, whooper swan, eider, shelduck and a great many other bird species have been given protection status. the kaali meteorite cratersBut on the whole, the islands are somewhat poorer in wildlife species than the mainland. Neither mole, mink, nor otter can be found her, the lynx and the brown bear are but infrequent guests.

Dolomite, limestone, curative mud, mineral water, sand and gravel, ceramic clay are the major local minerals.

The Kaali meteorite craters are unique. The biggest crater is surrounded by a bank and it is covered with shady trees which have formed a natural park. The depth of the crater is 16 metres, the diametre 110 metres.