It didn't take long to drive the loop - maybe about 30 minutes. There are quite a few stops and pull outs along the way, I spent about 90 minutes there because I needed to get back to for a 'date'.
My first stop was the volcano. It was fairly steep but quick climb, although I was a little winded when I got to the top...which I am blaming on the change of elevation and only having about 2 hours to 'adjust'. Climbing the volcano was very similar to climbing sand dunes and the view from the top was nice.
Other stops included seeing spatter cones and lots of lava. There are caves there as well, that you need a permit to enter - as much as I wanted to do this...I didn't because I didn't have a lot of time, although I did go over to one just to look at it from the outside.