The volcano looms over the Java Sea from the northern shore of the island of Sumbawa, which lies towards the eastern end of the former Dutch East Indies, now Indonesia.
Every now and again Mount Tambora erupts. Its 1815 explosion was possibly the most destructive ever recorded.
Tambora stood over 14,000 feet high in 1815, but when it blew its stack it hurled more than 4,000 feet off the top of it, leaving a crater more than four miles across and 2,000 feet deep.
On 5 April a modest eruption occurred, as if the volcano was practising, followed by thunderous rumbling noises. Ash began to fall and on 10 April there were more rumblings that sounded like cannon.
That evening the eruption moved into full force with an explosion that was heard more than 1,200 miles away in Sumatra. The ground shook as massive boulders were tossed about like pebbles and caused havoc in all directions.
Columns of flame shot up from the mountain and melded together to carry a plume of gas, dust and smoke miles up into the sky. Rivers of incandescent ash poured down the slopes at more than 100 miles an hour, destroying all in their way before they hissed and boiled into the sea. Ships in harbours were trapped in rafts of pumice stone, while tsunamis were driven across the Java Sea. Volcanic ash fell as far away as Borneo.
Ash and debris rained down for weeks and houses for miles around collapsed. Fresh water sources were contaminated and crops failed, while sulphurous gas caused lung infections.
It is thought that 10,000 people had been killed instantly, but thousands more died of starvation and disease and the death toll in Sumbawa and neighbouring islands has been estimated at anything from 60,000 to 90,000.
Stamford Raffles, then governor of Java, which had been taken over by the British during the Napoleonic Wars, sent an officer to Sumbawa to report on what had happened. He found there were still dead bodies lying around, the villages were almost entirely deserted and most of the houses had fallen down.
The few survivors were desperately trying to find food. An epidemic of violent diarrhoea had broken out, thought to have been caused by volcanic ash contaminating the drinking water, and had caused many deaths.