The Dink Network

Hitting the doors into Machine Mountain at this stage of the game is a futile operation - even if you kill the frog-bot that comes out, another will then appear - I think you have a couple of seconds to exit the screen before it locks up, but that is all - the point or lesson being: this is a dangerous place... don't go here just yet.

As for burnable trees, there are two together just right of the little fountain thingy with rocks - they are somewhat disguised - as that is what makes it a game, finding the entrances etc...