The phrase "edge of a cliff" means being at the very steep and dangerous part of a tall, rocky hill or mountain, where one wrong step can lead to falling off and getting hurt or even dying. Full definition
You not only want to leave your readers hanging on edge of the cliff with your character, but you also want to give them a tiny sneak peek of what's on the other side. (speculationsediting.com)
This Villa's view is simply nothing like you've experienced before.To our surprise, for being so high and at edge of a cliff, it wasn't windy or cold.The service was incredible, Veronica, Leno and Maria were all wonderful. (luxuryretreats.com)
You'll see daredevil visitors leaping off from the rocky edges of the cliffs above into the water below. (dominican-guide.com)