An island

You can feel the sun on your skin and the sand under your back. Hear the crashing waves. Smell the salt in the air... you open your eyes to blue sky.

You sit up... you feel great. A slight tingling sensation all over, but that's it. You always burned easily, and have a much deeper tan than you did in the lab, so have obviously been out in the sun for a while... but no sunburn. Probably the nanites.

Looking around, you find you're alone. There's the waves, a beach house, the beach, a floating dock with no boats, a forested area in easy view... and that's pretty much it. Frowning, you get up... and realize you're naked. Well... that sucks, but as you examine yourself... the nanites seem to be working as you designed: Your scars are gone, your skin is smooth, and your muscle tone is better than it was before. If the 'test' imposed on you is following protocol... you're probably screwed. If they're cutting corners... you're still probably screwed, but you might at least be able to get to civilization. Still... only one way to find out.

You start walking along the beach, keeping the waves to your left. You find your stamina is a lot better than it was, you're not even slightly tired when you see the same beach house and your own footprints in the sand after maybe an hour's walk. Okay, yes, an island with only the one building - at least, visible from the beach - and one dock... and no other land in sight. That's no good at all. Well... nothing to do but check the building....