This Twitter post by MK Taxi (also linked here) is a great example of sacred space in Japanese religion. The “gate” you see above is known as a torii (鳥居), and is only used for Shinto shrines. It helps to mark the boundary between the sacred interior and the mundane exterior, and are nearly universal in Shinto.
Buddhist temples by contrast, do not use torii gates. Instead, they use sanmon (山門) or “mountain gates”, a throw back to Buddhist temples in China which were often built on top of mountains. Even city temples still have such a gate, even if a small one. While Buddhism and Shinto are quite different religions, the sanmon fulfills a roughly the same role: marking the boundary between temple interior and mundane world outside.
The notion of sacred space is not limited to Japan, but it’s interesting to see how it manifests from culture to culture.