Jellyfish Lake, Republic of Palau, Micronesia. The jellyfish evolved in the lake without any predators, and over time grew vegetarian and lost their ability to sting. Their red color is a result of an algae diet. The water in the lake is salty and connected underground to the ocean but not even the tiniest jellyfish can get in or out.
One of my favorite places I traveled to in my late 20's was to a small castle ruin in Wales. It was a quiet place & I got headphones with narration to walk thru while listening to stories of the battles, day-day lives of the great old warriors of Wales. Great memory!