Trees have been around for about 370 million years, and as you can from these incredible pictures, there's a good reason why they've survived for so long. Whether they're growing in the middle of gale-force winds, on the tops of rocky platforms, inside concrete tunnels, or even growing out of each other, trees know how to survive in places that few living organisms can, which explains why the planet is host to around 3 trillion adult trees that cover an estimated 30% of the earth's land. Considering that plants produce the vast majority of the oxygen that we breathe, we should all think ourselves very fortunate that trees are as resilient as they are. We wouldn't even be here if they weren't.