I crush the iron, yet flow like a stream, A cradle for rebellion, a teenager's dream. I am hard as a mountain, I roll with the beat, And I stand at the altar where heavy keys meet. What am I?

This nut has a hard shell and if you crack it open you'll find it looks rather like a brain. Because of that it can occasionally be used as an insult, either comparing someone's brain to the size of this, or just calling them this directly. When eaten on its own it can have a controversial bitter taste, but has found some popularity as a vegan substitute for mince.

I wait until you’ve settled in, then let my evening song begin. You hunt me down with every swat, yet somehow miss me…quite a lot.

I start off with a smooth, oval-shaped body and a long, thin tail. My looks don't improve when I grow up to have chunky, short-legs and dry, bumpy skin covered in warts.

Found on the coast, I contain sun and sand and sea. Many people come visit on vacations, usually in the summer.