This video shows you the amazing active volcano Pacaya in Guatemala and us climbing it.
UPDATE: Thousands Flee their homes as Pacaya Volcano erupts (BBC News May 2010).
Climbing Pacaya volcano was quite an exhilarating experience. We left Antigua at 06.00 in the morning and arrived at the base of the volcano at 07.30 and started the summit trail. The initial climbing was through a forest trail. Suddenly the trail ended and the land in front of us was barren and grey looking like pictures from the moon. You could still see the beautiful landscape around us, but rivers of grey had run into it. At this point we started climbing through dunes of grey sand dust and the wind blowing was strong and cold.
The last part of the climb, to the point where hot burning lava is flowing, was the hardest part. The trail was very steep and you had to climb in either lava sand which kept disappearing under your feet (so that you basically took one step forward and two back) or you had to balance on the dry rivers of hot lava rock. Now for those of you who have not seen a lava stone, let me tell you "it is very very sharp and putting your hand down would surely cut you. But the color and formation is amazing it looks like silver and is at times shaped like waves.
While climbing the old lava waves you could feel the heat from underneath getting increasingly hot and finally we reached the point where the river of hot, burning lava came flowing out it was truly magical.
Good advice: I suppose it is needless to say that you need warm clothes and solid hiking boots to climb the volcano. It would be impossible to climb the sharp rocks in thin shoes or stand the cold without a proper jacket and pants.
Directions: You can buy a ticket to the volcano from Antigua for about 50 quetzals. This covers a return trip to the volcano. At the base of the volcano you pay 40 quetzals for entering the parquet. Some travelers report having a guide with them with a shot gun for protecting (against robbery). We had a good guide but without a gun. The tours leave Antigua at either 06.00 in the morning or 14.00 in the afternoon. I would recommend you taking the early morning trip because climbing down from the volcano in pitch dark (the last trip) is dangerous.
Good luck.