I know a man-made Ghana, which actually the biggest in West Africa, i dunno know if you know about it, Volta Lake, unfortunately it not as crystal clear as the one your narrating however there are some Spas and recreational facilities around it where you can go for a holiday retreat. There's also a nice Island in a town Called which requires about two hours in a boat.

Is nice to know that these beautiful sceneries exist, visiting these places helps take your mind off the hustle and bustle of life. Thanks for the post