Rock formations of Arches, Bryce Canyon, Al Naslaa, and Madain Saleh. And whatnot.
Cave denizens, of Interest.
Stalactites are formed from water running through what is generally limestone. The accompanying Stalagmites are then brought into being from the calcite which drips from said stalactite. Seems to work out pretty well.
Interesting composite organisms.
Fire, in various states, including vortices.
Dramatic moments, Dept. of Electricity.
Tesla coils, in various states/conditions.
The drawings of pioneering neuroscientist Santiago Ramón y Cajal. The 1906 Nobel prize winner detailed the microscopic, serpentine arborizations of brain cells, among other exploits. As a precocious 11 year old boy, he also managed to raze his neighbor’s gate with a homemade cannon.