North Shore, Lake Superior, Minnesota, USA.
About 20 min exp.
I was recently in Yosemite National Park in California, and learnt that they used to light a huge fire on Glacier point and then they would push the fire over the edge and let it drop 3000ft to the valley below. That would make a great photo.
This is on a small scale. This fire falls 8ft into the lake and was perfectly safe.