80% of Greece is located on which peninsula?

The Balkan Peninsula includes all, most, or part of the countries of Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Hungary, Kosovo, Macedonia, Montenegro, Romania, Serbia, Slovenia and the European part of Turkey (3% of the total land area of the country). Italy also makes the list depending on which set of geographers is defining the region, because of the region of Trieste.

80% of Greece's land mass is included on the Balkan peninsula, since the remaining 20% of Greece is islands.

Various watery natural borders of the peninsula include the Adriatic, Aegean, Mediterranean, Ionian, Marmara and Black Seas. Its northern border is generally cited as formed by parts of the Danube, Sava and Kupa rivers.

The total area of the Balkan Peninsula is slightly smaller than that of Spain, at about 470,000 sq km (181,000 sq mi).

Regarding the choices, not all are peninsulas. The Iberian Peninsula includes primarily Spain and Portugal; The Balearic Sea is located between the eastern coast of Spain and its islands of Minorca and Majorca. The Baltic Sea is bordered mostly by parts of Sweden, Finland, Latvia, Estonia and Lithuania, Russia and Poland.