As a child and as an adult, I've always loved tide pools, there are always cool animals to be found, whether it's the coast of North Wales or more tropical climes...
One of my most vivid memories is of a particular bay in northern Spain, in a town called Llanes iirc, where the tide receeds to reveal a rock with a tunnel which can be walked through to come out of the other side while wading through 0.5m of water, with all kinds of shrimp and fish wandering about around your feet.
One time, further out in the bay on a particularly low tide, a young Sapnish boy entertained a load of us fishing for something with a chunk of fish tied to some bale string... he was obviously determined to catch whetever it was he was after, and so drew what amounted to a small crowd. Eventually he felt a tug and started to pull the chunk back to the surface, to reveal a sizeable octopus which was wrapping it's tentacles up the rope, and once he grabbed it, all over the boy's arm. The noise and sight of the suckered tentacles being pulled of his arm only for another two or three tentacles to grab him will never leave me.
Sadly, and much to my (and some others) dismay, he then proceeded to reach inside the beautiful cephalopod, wrench it inside out and beat it several times on the rocks. He then left it for dead.
That made me sad.
I'll always return my "catch", especially if I found anything as impressive as that.