Offshore flooded caves, so-called ocean blue holes, are extensions of the sea, subject to the same heavy tides and host to many of the same species found in the surrounding waters. Inland blue ...

The show, called “Ao no Dokutsu (blue cave) Shibuya,” features about 600,000 blue LEDs along an 800-meter stretch between Shibuya Koen-dori street and rows of zelkova trees in Yoyogi Park in ...