We have several, for a couple just finding our way in the Lifestyle, they were pretty adventurous:
On the roof of our resort in Isla Mujeres last Jan. Fun under the stars and later twice in afternoon within visibility from balcony rooms in another building. I'm usually pretty vocal and had to keep it down.
In front of a cute couple in a resort hottub in Jamaica, they were kind enough to reciprocate. (Which has launched us into the next phase of expanding our Lifestyle horizons.)
Later at that same resort (no, not Hedo) on the beach at night. Guard caught us the second time but left us alone.
On the porch at night at our lakefront condo, fisherman not 30 feet away. Again, we had to keep it down, which added to the excitement.
The hottest for me was at night, on a beach, in a light rain, on a hammock. The motion was just perfect, very romantic and wild-it was the most multi orgasmic event of my life.