Explanation:

Mount Etna, or Etna, is an active stratovolcano on the east coast of Sicily, Italy, in the Metropolitan City of Catania, between the cities of Messina and Catania. It lies above the convergent plate margin between the African Plate and the Eurasian Plate.

Krakatoa, or Krakatau, is a caldera in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung

Mount Popa is an extinct volcano 1518 metres above sea level, and located in central Myanmar in the region of Mandalay about 50 km southeast of Bagan in the Pegu Range. It can be seen from the Ayeyarwady River as far away as 60 km in clear weather.

Mount Vesuvius is a somma-stratovolcano located on the Gulf of Naples in Campania, Italy, about 9 km east of Naples and a short distance from the shore. It is one of several volcanoes which form the Campanian volcanic arc.