Low cost drones with video cameras allow us to see things impossible to otherwise. I have studied volcanology yet this video gives a real-time feel for it. Down to the ash and volcanic bombs such a feel was unattainable till now, and it is amazing to watch.
It is also amazing that the drone survived it as you watch drops of molten lava fly by within inches.
Quad-copter Drones capable of doing this can be bought for less than $1,000.
Yasur volcano on Tanna island, Vanuatu.