Sand.
Even without looking around, you know that you are lying on sand.
The sun hangs dully in the sky, at about mid-morning.
A light tide laps at your heels, dousing your shoes and ankles.
Pushing yourself up with one hand, you survey the landscape around you.
On one side, a massive expanse of water stretches out as far as the eye can see, its depth immeasurable.
Turning to face the other expanse, a perfectly flat sand beach spreads seemingly infinitely in the other direction.
At your feet, you see the wet sandy mess you are standing in, the spot where the sand and sea meet.

A dull ringing in your head brings you back to the current situation.
You have no idea where you are.
You have no idea who you are.
You have no idea what you are doing there.

All of a sudden, an arrow appears, instantaneously dug in the sand.
With no other options, you head in the direction of the arrow.