This is a modern art design located in Switzerland. At first glance, it looks like a four-sided mirror or something, but in fact, it is a restroom: all four walls are made of one-way transparent glass, allowing natural light to stream in from all sides. This makes the restroom appear bright, spacious, clean and grand without using a single light bulb. People outside cannot see what's happening inside, but those inside can clearly see the outside world. Friends who are using the restroom no longer have to stare at the same old tiles. You can enjoy the scenery outside while taking care of your business, and even count how many people are waiting in line to use the restroom :) .