The geographic region of Thessaly is located in the eastern part of mainland Greece, stretching approximately 14,000 square kilometers and its population amounts to approximately 735,000 inhabitants.

North is adjacent to the prefecture of Pieria, Kozani, Grevena, west to the prefectures of Ioannina and Arta, south to the counties of Aetoloacarnania, Evrytania, Fthiotida and Euboea and east to the coast of the Aegean Sea.

The district of Thessaly, surrounded by mountains who enclose the Thessalian plain and are the most important in the region. The climate of Thessaly is continental and the configuration of the ground is 50% mountainous and 50% flat and in its boundaries is included the plain of Thessaly, which is separated by a low mountain range on the western plain of Trikala and the eastern plain of Larissa.

Apart from these basic plains of Thessaly, there are the plains of Almyros, Velestino, Amouri, Elassona, and the mouth of the river Peneus.

The plain of Thessaly is entirely crossed by Penaeus river, which is the largest river in Greece with a total length of 205 km. Penaeus creates breathtaking landscapes and eventually flows into the Aegean Sea. The main tributaries are Ennipefs, Klinovitikos, Portaitikos, Pamisos and Lithaios.
Also, a part of the western mountainous Thessaly, is crossed by the river Achelous.

In Thessaly and specifically its eastern part, there is Olympus mountain, which is the highest mountain in Greece and across of it, is located Ossa (Kissavos), where is formed the valley of Tempi.

Then,Kambounia mountains rise separating Thessaly from Macedonia and western of them are located Chasia mountains and Antichasia mountains.

In the northwestern part of Thessaly there are the mountains Liggos, Lakmos and Koziakas, where springs Peneus river.

Agrafa mountains and Orthi are located in southern Thessaly, and eastern, in Magnesia, rises Pelion, where there is rich vegetation.

In western Thessaly, in Kalambaka area, rise the peculiar rocks of Meteora.

In Thessaly there were many lakes, which had been dried, as Carla, Askourida and Nessonida. Today there is only the artificial lake of Plastiras, in Karditsa Prefecture.

The territory of Thessaly in combination with its abundant waters result in the development of agriculture and production of cereals, pulses, fruits, vegetables and tobacco, while its meadows contribute to the development of animal husbandry.