What is the oldest active volcano on Earth?

Mount Etna, or Etna, in the Metropolitan City of Catania, between the cities of Messina and Catania, is an active stratovolcano on the east coast of Sicily, Italy. It lies between the African Plate and the Eurasian Plate, above the convergent plate margin. It is the highest active volcano in Europe outside the Caucasus and, with a current height of 3,326 m (10,912 ft), it is the highest mountain in Italy south of the Alps, although this varies with peak eruptions. With a basal diameter of 140 km (87 miles), Etna occupies an area of 1,190 km2 (459 sq mi).

This makes it the biggest of the three active volcanoes in Italy by far, being around two and a half times the height of Mount Vesuvius, the next largest. In the whole of the European-North-African area west of the Black Sea, only Mount Teide on Tenerife in the Canary Islands surpasses it. In Greek mythology, under this mountain, the deadly monster Typhon was imprisoned by Zeus, the god of heaven and thunder and the king of gods, and under it were also said to be the forges of Hephaestus.

The oldest volcano is Etna, and it's about 350,000 years old. It seems that most of the active volcanoes we know about are less than 100,000 years old. Volcanoes grow because, adding layers and height, lava or ash accumulates on the volcano.