If you're visiting Japan soon, make sure you keep an eye out for these gorgeous manhole covers on the streets.

There are over six thousand designer manhole covers in Japan, and each falls under a different design category, according to Colossal. Some of the categories include trees, landscapes, floral patterns and birds.

Photographer S. Morita spent a few years traveling the country to document this obsession, and has collected a huge number of images.

Check out some of Morita's images below, or click here to view more.