Baltic Sea Trivia
0Loading crowd target
0Loading crowd target
6correct to beat the crowd
47 free Baltic Sea trivia questions with answers — geography quiz, new questions added Sep 2026.
Baltic Sea trivia for geography fans, cruise passengers, Nordic and Baltic expats and pub-quiz setters. The quiz starts with the basics - which nine countries touch the sea, where it drains, why its water is barely salty and why the shipworm leaves old wrecks alone - and then works through the gulfs, islands and straits: Bothnia and Finland, Gotland and Bornholm, Åland, the Curonian Spit, the Sound Dues once collected at Kronborg. History gets its share: Tacitus and Adam of Bremen naming the sea, Vikings calling it Austmarr, the Hanseatic League and its cogs, Sweden's dream of a Mare Nostrum Balticum, Peter the Great founding St Petersburg on the Neva, the loss of the Vasa in 1628, the sinking of the Wilhelm Gustloff in 1945 and the ferry Estonia in 1994, Cold War submarines, the Øresund Bridge, Nord Stream and the 'NATO lake' of the 2020s. Roughly a third of the questions are easy, a third medium and the rest will stretch anyone who did not grow up on its shores. Every answer has been checked against a reference page and each question shows its source once you have answered.
30 of 47 questions with answers and explanations. Play the quiz
Q 01Which sea fortress did Sweden build off Helsinki from 1748?
Suomenlinna
Suomenlinna was built by Sweden to guard against Russia, yet in 1808 its commander surrendered it to Russian forces, for reasons that remain unclear.
Q 02The Baltic is often called the world's largest basin of what kind of water?
Brackish
Brackish water fills the Baltic because rivers draining an area over four times its size pour in fresh water, while ocean salt can enter only through the narrow Danish straits.
Q 03Which sea does the Baltic drain into through the Danish Straits?
The Kattegat
The Kattegat is shallow, and its reefs and uneven seabed make it a tricky passage for ships.
Q 04Which artificial waterway, opened in 1895 through Schleswig-Holstein, links the Baltic to the North Sea?
The Kiel Canal
The Kiel Canal was sought by merchants and by the German navy, which wanted to link its Baltic and North Sea bases without sailing around Denmark.
Q 05What is the northern arm of the Baltic, lying between Sweden and Finland, called?
The Gulf of Bothnia
The Gulf of Bothnia's northern shores rise about 1 cm a year, as the land rebounds from the weight of the ice-age ice sheet.
Q 06Which arm of the Baltic connects the sea to Saint Petersburg?
The Gulf of Finland
The Gulf of Finland's storm surges long flooded Saint Petersburg, so a flood barrier abandoned in the 1990s was finally completed in 2011.
Q 07At which research site on the Baltic island of Usedom did Wernher von Braun's team develop the V-2 rocket?
Peenemünde
Peenemünde developed the V-2, but the rockets were mass-produced largely by concentration camp prisoners, at least 10,000 of whom died making them.
Q 08Which Roman historian, writing about the Germanic tribes, called the Baltic the 'Suebic Sea'?
Tacitus
Tacitus may never have set foot in Germania himself, so his account of its tribes may rest largely on second-hand reports.
Q 09Which 18th-century Swedish scientist had marks cut into coastal rocks to measure the Baltic's apparent fall?
Anders Celsius
Anders Celsius's marks tracked a retreating shoreline, and the cause is now known to be the land itself rising, not the sea falling.
Q 10In German, Swedish, Danish and most other Germanic languages the Baltic is called the equivalent of what?
East Sea
German Ostsee and Swedish Östersjön both mean East Sea, yet Estonian flips the idea: its name, Läänemeri, means West Sea.
Q 11Which film spaceship did some liken to the sonar 'anomaly' Swedish treasure hunters found on the Baltic seabed in 2011?
The Millennium Falcon
The Millennium Falcon comparison did not hold up: a geologist who examined the divers' samples found only natural rock.
Q 12Which gem-like material do beachcombers famously gather along the Baltic's southern shores after storms?
Amber
Amber is fossilised tree resin: waves tear pieces from the seabed and storms cast them ashore, where people still collect them by hand.
Q 13Which federation of merchant towns, grown from Lübeck, dominated Baltic trade from the 13th to 16th centuries?
The Hanseatic League
Q 21The ferry MS Estonia sank in September 1994 while sailing between which two cities?
Tallinn and Stockholm
The Estonia had left Tallinn for Stockholm when her bow visor tore away and pulled open the car-deck ramp, letting in the water that sank her; 852 people died.
Q 22Why have wooden wrecks such as the Vasa survived so well on the Baltic seabed?
Shipworms are rare there
Shipworms are rare there because they need saltier water than most of the Baltic offers, so wooden wrecks last far longer there than in the oceans.
Q 23Why did the Swedish warship Vasa sink minutes into her maiden voyage in 1628?
The Hanseatic League grew from Lübeck's 1241 pact with Hamburg into a network of some 200 towns; its Kontors in London, Bruges, Bergen and Novgorod enjoyed their own legal privileges.
Q 14Which type of medieval merchant ship was pictured on the seals of Baltic trading towns such as Lübeck?
The cog
The cog was known mainly from such seals until 1962, when dredging in Bremen's river Weser uncovered a well-preserved wreck from about 1380.
Q 15Which Latin phrase named the goal of Poland, Denmark and Sweden's 16th–17th-century Baltic wars?
Dominium maris baltici
Dominium maris baltici means lordship over the Baltic; Sweden came closest to it, until Russia defeated Sweden in a war that ended in 1721.
Q 16At which castle near Helsingør did Denmark collect its Sound Dues from ships passing through the Øresund?
Kronborg
Kronborg's guns enforced the Sound Dues: a ship that refused to pay could be fired on, until Denmark abolished the toll in 1857.
Q 17Which Russian ruler founded Saint Petersburg at the mouth of the Neva to secure a Baltic outlet?
Peter the Great
Peter the Great had earlier spent 18 months touring Western Europe incognito, a journey known as the Grand Embassy.
Q 18Where in the Baltic did an Anglo-French force destroy Russia's Bomarsund fortress in 1854?
Åland
Åland's Bomarsund fortress was captured and destroyed in 1854, and the peace that ended the war left the islands demilitarised.
Q 19Which German refugee ship, torpedoed in January 1945, is thought to be history's deadliest single-ship sinking?
Wilhelm Gustloff
The Wilhelm Gustloff sank within an hour, and many who survived the torpedoes and the chaos on board froze to death in the icy Baltic.
Q 20What ran aground near Sweden's Karlskrona naval base in October 1981, setting off a Cold War standoff?
A Soviet submarine
A Soviet submarine, called U137 by the Swedes, had run aground, and Swedish radiation tests suggested it was carrying nuclear weapons.
She was top-heavy and unstable
She was top-heavy and unstable, so a wind barely stronger than a breeze heeled her over, and about 30 people died when she sank.
Q 24In which Swedish town was the 1397 union of Denmark, Norway and Sweden under one monarch agreed?
Kalmar
Kalmar gave its name to the union, but Sweden broke away for good in 1523, when it elected its own king.
Q 25Which Baltic fish is fermented to make Sweden's notoriously pungent surströmming?
Herring
Herring keeps fermenting inside surströmming's tins, which is why airlines such as British Airways banned the cans as potentially explosive.
Q 26Which Baltic seal gives birth only on the winter sea ice, hiding its pup in a snow lair?
Ringed seal
The ringed seal raises its pup in snow lairs on the ice, so winters with too little ice mean weaker pups and more of them dying.
Q 27What are the occasional pulses of salty, oxygen-rich North Sea water that flush the deep basins called?
Major Baltic inflows
Major Baltic inflows are the deep basins' only real supply of fresh oxygen: the dense, salty North Sea water sinks along the seabed and pushes out the stale water.
Q 28What mainly fuels the algal blooms that starve the Baltic seafloor of oxygen?
Nitrogen and phosphorus
Nitrogen and phosphorus feed the blooms, and as the dead algae sink and rot, their decay uses up the oxygen near the seabed.
Q 29Which is Sweden's largest island, home to the walled medieval town of Visby?
Gotland
Gotland's Visby grew rich as a Baltic trading hub, but in 1361 Denmark's King Valdemar IV invaded the island and held the town to ransom.
Q 30Which Danish Baltic island is famous for its round churches and the fortress ruin of Hammershus?
Bornholm
Bornholm lies east of the rest of Denmark, so travellers from Copenhagen often cross into Sweden and take a ferry from Ystad.