Have you ever noticed metal rings attached to Portland's sidewalks and wondered what they were?

Once upon a time, those metal rings in the cement were used to tether horses while their owners went about their business in the city.

However, these days not many city-dwellers are riding around on horses, leaving these little pieces of Portland history searching for a purpose. And one local has given that to them, turning the rings into a community art project.

Artist Scott Wayne Indiana was struck by the notion of days when cars were not filling our streets.

In 2005, he started bringing horses back to the city with the Portland Horse Project.

Indiana would attach toy horses to the rings throughout the city.

The project began to grow, and soon Portlanders were tethering up toy horses all over the city. Many of the horses are brightly painted or have little notes or special touches that tell a story.

"I grew up loving the rings, walking around Old Town with my grandpa and my grandparents. I've always had a fascination with the rings myself personally, and I know a lot of other people have too," Indiana said.

There is something magical about them [...] I feel so much gratitude to be connected in any way... in a way that will live on after I'm gone ...

The Portland Horse Project has turned into a whole community, including a Facebook page where anyone can join and share images and stories of the horses they place around the city.