The Baltic Sea borders Poland, Lithuania, and Russia.
Quick fact: The Baltic Sea is a brackish inland sea in Northern Europe. It directly touches Poland, Lithuania, and Russia. Stretching about 1,600 kilometers (994 miles) from north to south, it covers roughly 377,000 square kilometers (145,560 square miles). Its coordinates run from 53°N to 66°N latitude and 10°E to 30°E longitude.
What's the geographic context of the Baltic Sea?
The Baltic Sea sits at a major maritime crossroads connecting Scandinavia to Central and Eastern Europe.
This sea links industrial ports like Gdańsk in Poland, Klaipėda in Lithuania, and Kaliningrad in Russia. That connection fuels trade and cultural exchange. The sea also shapes the northern and western borders of Poland and Lithuania, reinforcing their identities as Baltic states. By 2026, it remains one of the world’s most ecologically sensitive seas because of its enclosed shape and heavy human use.
Which countries share the Baltic Sea's coastline?
Poland, Lithuania, and Russia all share direct coastline with the Baltic Sea.
Other countries with Baltic coastlines include Sweden, Finland, Estonia, Latvia, Denmark, and Germany. But the three you asked about—Poland, Lithuania, and Russia—sit right on its shores.
How long and wide is the Baltic Sea?
The Baltic Sea stretches about 1,600 kilometers (994 miles) from north to south.
Its width varies, but it’s at most around 193 kilometers (120 miles) across. The sea’s total area covers roughly 377,000 square kilometers (145,560 square miles).
What's the average depth of the Baltic Sea?
The Baltic Sea has an average depth of about 55 meters (180 feet).
That’s not very deep compared to oceans. The deepest point, Landsort Deep, plunges to 459 meters (1,506 feet). Most of the sea stays fairly shallow, which affects how water circulates and ecosystems function.
Where’s the deepest point in the Baltic Sea?
The deepest point is Landsort Deep, reaching 459 meters (1,506 feet).
It sits southwest of Stockholm in Sweden. That trench is the sea’s lowest spot by far, and it plays a key role in how water and nutrients move through the basin.
How much of the Baltic Sea's coastline belongs to Poland?
Poland’s coastline along the Baltic Sea measures about 528 kilometers (328 miles).
That’s a long stretch of sandy beaches and busy ports. Compare that to Lithuania’s much shorter coastline of roughly 99 kilometers (62 miles).
How much of the Baltic Sea's coastline belongs to Lithuania?
Lithuania’s coastline along the Baltic Sea is about 99 kilometers (62 miles) long.
It’s narrow but packed with resorts and historic fishing villages. That coastline gives Lithuania its only direct access to the sea.
What type of ecosystem does the Baltic Sea have?
The Baltic Sea has a unique brackish ecosystem.
Freshwater from over 200 rivers mixes with limited saltwater from the North Sea through the Danish straits. The result? A sea that’s neither fully fresh nor fully salty. That mix supports species that can handle both conditions, though pollution and overfishing have taken a toll in most cases.
How did the Baltic Sea form?
The Baltic Sea is a remnant of the ancient Littorina Sea, formed after the last Ice Age about 8,000 years ago.
Geologically speaking, it’s a young sea. As glaciers melted, water filled the basin left behind. The Littorina Sea stage marked a time when saltwater inflow increased, shaping the Baltic we know today.
What historical trade routes existed around the Baltic Sea?
Amber trade routes date back to the Bronze Age along the Baltic’s coasts.
Archaeologists have found evidence that coastal settlements thrived for millennia. Amber from the Baltic was highly prized across Europe. Those early trade networks laid the groundwork for the region’s later economic ties.
Are there ferry routes between Poland and Lithuania across the Baltic Sea?
Yes, ferries connect Poland and Lithuania across the Baltic Sea.
Companies like Tallink Silja and Polferries run routes between Gdańsk and Klaipėda. The trip usually takes 12–15 hours. It’s a scenic way to travel, though weather can sometimes cause delays.
How long does the ferry from Poland to Lithuania take?
The ferry from Gdańsk to Klaipėda typically takes 12–15 hours.
That’s overnight for most travelers. The crossing is popular with tourists and locals alike, offering a chance to see the sea up close.
Is the Baltic Sea safe for swimming?
The Baltic Sea is generally safe for swimming near shore, though currents can still be unpredictable.
Its low salinity (0.5–0.8%) makes it less harsh on skin and eyes than ocean water. Still, always check local conditions before jumping in. Some spots have strong undercurrents, especially after storms.
What are some popular coastal towns in Poland and Lithuania along the Baltic Sea?
Poland’s Sopot and Lithuania’s Palanga are two of the most popular coastal towns.
Sopot is famous for its sandy beach and lively boardwalk. Palanga draws visitors with its dunes, resorts, and historic amber museums. Both towns offer a mix of relaxation and nightlife during the summer months.
Why is the Baltic Sea ecologically sensitive?
The Baltic Sea is ecologically sensitive because of its enclosed shape and heavy human use.
(Honestly, this is one of the most polluted seas in the world.) Nutrient runoff from agriculture and cities fuels algal blooms. Limited water exchange with the North Sea makes recovery slow. That’s why conservation efforts are so important here.
Edited and fact-checked by the MeridianFacts editorial team.
