Who says you need an actual mountain bike for a mountain? “Monkey Mountain” (Shoushan) in Kaohsiung, Taiwan.

Took a run up Shoushan (aka "Monkey Mountain", due to the large population of monkeys that hang out around the trails) on my Hybrid, a Giant Escape I've let sit more often than not. I've been up some of the trails on my road bike actually so knew it was doable with a hybrid easily enough. A nice ride around sunset without many people on the weekdays, up old mining roads which are partially (roughly) paved and part rough volcanic rock. Great views even from the lower trails here, and monkeys to keep you company and steal your food if you're not cautious.