Indonesia's Merapi volcano has been spewing thick smoke for nearly a week and volcanologists say it may erupt at the end of the month.

In April 2006, the situation concerning Gunung Merapi gets more serious. The volcano is on eruption watch as scientists expect the volcano to erupt in one to two weeks from now. The pictures here show quiet foothills of Gunung Merapi after parts of the population have evacuated.

Following are five facts about the volcano:

• Gunung Merapi, or Fiery Mountain, located in the southern area of central Java, overlooking the ancient royal city of Yogyakarta, is the most active volcano in Indonesia.
• Merapi has been witnessing small eruptions every two or three years, bigger ones every 10-15 years, and very large ones every 50-60 years.
• The biggest eruptions occurred in 1006, 1786, 1822, 1872 and 1930. The eruption of 1006 was so bad that the existing Hindu kingdom was apparently destroyed while in 1930 more than 1,300 people were killed.
• The 1994 eruption claimed more than 60 lives, but the 3,000-metre (9,800-ft) volcano is considered sacred by local people who believe a supernatural kingdom exists atop Merapi. Every year a priest climbs to the top to make an offering.
• The country has the world's highest density of volcanoes, located in the so-called 'Ring of Fire', a vast zone of frequent earthquakes and volcanic eruptions looping around the Pacific Ocean including Indonesia and Japan. Of these, 128 are active and 65 listed as dangerous.