I have friends that own a small beach cabin on the lake. While space is at a minimum, they have a small spot of grass where they have a hammock. I fell asleep there once, swinging in the breeze, listening to the seagulls and waves on the shore. When I woke, I felt so relaxed!
Granted it was 4th of July weekend, so I had a day off, and could afford the time to nap, but between the gentle movement and outside air, I was asleep before I knew it, and I slept soundly.
So, find a hammock, crawl in and take a nap!