I am an enthusiastic amateur rock botherer, what got me hooked was wondering why mountains on why one side of our island are far more rugged, and the river gorges far harder to traverse, than the other.

Turns out that's what happens when on either sides of a subducting plate boundary.

What I love though, is that the fault that marks the boundary, was initially discovered by someone mapping natural hot springs and noticed they formed a rough line trending SW - NE.