The dark of night reveals large clusters of bright white lights in the East Sea (Sea of Japan), just off the coast of South Korea in the left third of this image from November 6, 2017. There are no islands beneath these super-luminous aquatic constellations, only ocean.
Hundreds of fishing boats, each equipped with extendable booms loaded with super-bright lights, have gathered around a few productive fishing spots. The jury is still out as to why exactly this works, but apparently the bright light attracts squid. Lots of squid. Experts believe it’s probably a food thing: perhaps it exposes their unsuspecting prey, who themselves feed near the surface at night. Maybe it looks just enough like a school of bioluminescent prey animals to warrant a closer investigation. Whatever the reason, it REALLY works. Squid gather in droves around the boats, catches are huge, and sales of sunglasses around South Korean fishing ports have never been better.
Pyeongchang, site of the 2018 Winter Olympics, is a few short miles from the east coast of South Korea, and just 50 miles south of the border with North Korea. One more thing the night reveals - the comparative vacuum of electric lights on the northern side makes the border fairly easy to spot after dark.