Bridge

Sparrow watched the tide come in and out over the bridge many times. She didn't know what kept it there. Compared to the rest of the ocean it was kind of like an under water mountain, but the top of the mountain was level with the shore and the rest dipped down below. Like... inverted mountains. What was the opposite of a mountain, anyway?

At the current, Sparrow thought to see if she dug up enough of it, if the tide would some how replace it or it it would give way and wash the sands into the chasms below.

OH, chasm. That was the opposite of a mountain. Or at least one of them.

Feeling very smart, Sparrow turned her focus on to her definitely not stupid task of digging.