I saw this pool while traveling in Taiwan. It has a length of 1500 meters and a width of 100 meters. Its water is fed by a spring. Imagine you only need to make a turn for a 3000 meter swim while immersing yourself in natural clean spring water with blue sky and white clouds on top, blue mountains on the horizon, and trees along the side for you to enjoy.
Best of all, unlike any other crowded beaches and pools, there is no crowd to fight.