Estonia occupies 45,227 square kilometers on the eastern shore of the Baltic Sea, positioned between latitudes 57° and 59° N and longitudes 21° and 28° E. The country shares a 294-kilometer border with Russia to the east, a 339-kilometer border with Latvia to the south, and coastline along both the Gulf of Finland to the north and the Gulf of Riga to the southwest. The total coastline measures approximately 3,794 kilometers when accounting for the deeply indented mainland shore and the more than 2,300 islands that constitute roughly 10 percent of Estonian territory. The West Estonian Archipelago contains the largest concentration of these islands, with Saaremaa covering 2,673 square kilometers as the largest landmass in the Baltic states and Hiiumaa measuring 989 square kilometers as the second-largest Estonian island. The eastern border follows the Narva River for 77 kilometers from the Gulf of Finland to Lake Peipus, creating a natural boundary that has served as a strategic and cultural dividing line since medieval times.
The bedrock beneath Estonia consists primarily of Paleozoic sedimentary rocks from the Cambrian, Ordovician, Silurian, and Devonian periods, dating between 540 and 360 million years ago. These limestone, dolomite, sandstone, and clay layers lie nearly horizontal with a gentle slope from north to south, exposed along the northern coast where the Baltic Klint—a limestone escarpment—rises up to 56 meters above sea level near Ontika in northeastern Estonia. The Quaternary glaciation that ended approximately 12,000 years ago shaped the current surface topography, depositing till, sand, gravel, and clay in various thicknesses across the bedrock. The weight of the Scandinavian ice sheet depressed the earth's crust during glaciation, and Estonia continues to experience post-glacial rebound at a rate of approximately 2.5 millimeters per year along the western coast and 1 millimeter per year in the southeast, causing the relative sea level to drop and creating new land along shallow coastal areas.
The topography exhibits remarkably low relief, with the mean elevation measuring only 50 meters above sea level. Suur Munamägi in the Haanja Upland of southeastern Estonia reaches 318 meters above sea level, making it the highest point not only in Estonia but in the entire Baltic states and the highest point in the European Union north of 57°N latitude. The Haanja Upland itself forms part of a region of rolling hills created by terminal moraines deposited during the retreat of the last glaciation, contrasting sharply with the flat coastal lowlands that characterize much of northern and western Estonia. Between these extremes, elevation rarely exceeds 100 meters across the central plains and coastal zones, where the landscape consists of low-lying wetlands, former lake beds, and marine terraces created by changing sea levels during and after the glacial period.
Lake Peipus forms the fourth-largest lake in Europe by surface area, measuring 3,555 square kilometers when including its southern extension Lake Pihkva. Estonia controls the western portion of this lake, which reaches a maximum depth of only 15 meters and averages 7.1 meters deep, making it remarkably shallow for its size. The Emajõgi River flows 100 kilometers from Lake Võrtsjärv to Lake Peipus, draining central Estonia through Tartu and serving historically as a major transportation route. Lake Võrtsjärv covers 270 square kilometers in south-central Estonia with an average depth of 2.8 meters, making it the second-largest lake entirely within Estonian territory. These shallow lakes freeze completely during most winters, with ice cover typically lasting from December through April on Lake Peipus and providing historical winter crossing routes before modern infrastructure.
Wetlands cover approximately 22 percent of Estonia's territory, one of the highest percentages in Europe. Raised bogs—dome-shaped peatlands that receive water only from precipitation—developed over thousands of years in areas of poor drainage, accumulating peat layers up to 10 meters thick in some locations. Soomaa National Park in southwestern Estonia contains some of the most extensive and intact raised bog systems in Europe, covering 390 square kilometers established in 1993. The park experiences a "fifth season" typically occurring in March-April and sometimes in autumn when snowmelt and heavy rainfall cause the Halliste, Raudna, Lemmjõgi, and Navesti rivers to overflow, flooding forests and meadows to depths exceeding one meter and transforming the landscape into a temporary lake system accessible only by boat or traditional dugout canoe.
The West Estonian Archipelago creates a unique maritime environment where more than 500 islands larger than one hectare extend across the Baltic Sea west of the mainland. Saaremaa contains the Kaali meteorite crater, formed approximately 3,500 years ago when a meteor entered Earth's atmosphere and fragmented, creating nine craters with the largest measuring 110 meters in diameter and 22 meters deep. The impact event likely influenced local Bronze Age populations, appearing in later Estonian mythology. Hiiumaa features the Käina Bay on its eastern shore, a shallow brackish lagoon separated from the sea by the Kassari peninsula, creating important habitat for migratory birds. Vormsi, the fourth-largest Estonian island at 92 square kilometers, sustained a Swedish-speaking population from the 13th century until mass emigration to Sweden in 1944, leaving behind distinctive stone walls and traditional architecture. Ruhnu, located 37 kilometers from the nearest land in the Gulf of Riga, maintains the southernmost position of any inhabited Estonian island and historically belonged to Sweden before Estonia.
Coastal meadows formed through centuries of traditional livestock grazing along the Baltic shore create one of Estonia's most biodiverse habitats, supporting plant species adapted to periodic flooding by brackish seawater and grazing pressure. Matsalu National Park on the western coast encompasses 486 square kilometers including Matsalu Bay, established in 1957 as a nature reserve and expanded to national park status in 2004. The shallow bay serves as a critical stopover for migratory waterbirds using the East Atlantic Flyway, with spring migrations in April-May regularly exceeding 2 million birds including barnacle geese, pintails, and numerous wader species. Vilsandi National Park, established in 1910 as a bird reserve and expanded in 1993, protects 238 square kilometers of the Vilsandi archipelago off Saaremaa's western coast, where 160 islands and islets provide nesting habitat for Arctic terns, common eiders, and razorbills.
Forests cover 51 percent of Estonia's land area, having recovered from historical lows during the early 20th century when agricultural expansion and wartime logging reduced forest cover to approximately 20 percent. Scots pine dominates on sandy soils, Norway spruce on clay-rich soils, and various deciduous species including birch, aspen, and black alder in mixed forests and along waterways. Lahemaa National Park on the northern coast protects 747 square kilometers established in 1971 as the first national park in the Soviet Union, encompassing boreal forests, limestone cliffs, bogs, and four major peninsulas extending into the Gulf of Finland. The park contains the Käsmu Boulder Field where glacial erratics—rocks transported by ice sheets from Fennoscandia—lie scattered across the landscape, with individual boulders exceeding 10 meters in diameter. Old-growth forest remnants survive in protected areas, though commercial forestry removed most virgin forest during the 19th and 20th centuries.
The climate classification places Estonia in the humid continental zone with maritime influences moderating temperature extremes along the coast. Mean annual temperature ranges from 4.5°C in the northeast to 6.5°C on the western islands, with July averages of 16-17°C and February averages of -4 to -7°C. Annual precipitation measures 500-750 millimeters, distributed relatively evenly throughout the year with a slight summer maximum. The Baltic Sea freezes partially during most winters, with ice cover reaching its maximum extent in February-March when bays and the northern coast typically freeze while the open sea south and west of the islands usually remains ice-free. Snowfall occurs from November through March, accumulating to average maximum depths of 20-40 centimeters in lowlands and 40-60 centimeters in the southeastern uplands, though snow cover varies substantially between winters depending on the dominance of maritime versus continental air masses.