Growth in unusual places

Japan still amazes me from a natural standpoint - things seem to grow here so easily. I remember the first time we lived somewhere on the outskirts of Tokyo with a small garden area where we could plant some herbs. The dirt here was so fertile and a rich black color. Compare that to my yard in Australia full of clay soil, where it was almost impossible to grow things unless you built up planter boxes and used potting mix from the hardware store. It definitely wasn't as simple as putting stuff directly into the earth and seeing it thrive.

As a result of that, my surprise is still like a kid at a candy store when I see how easily things grow in Japan. Yesterday, when I was out on a walk with my family, we noticed some flowers growing out of the mossy stones near a neighbor's home.

Are there any unusual places you've noticed things growing since living in Japan? How does it compare to what you're used to back home?