A small army of volunteers has been working at Grant's Tomb in Manhattan’s Riverside Park to restore a historic mural.

The advocacy group CityArts is working on a 400-foot rolling mosaic bench that has surrounded Grant's Tomb since 1972.

Even the original artist, Pedro Silva, has returned to pitch in more than three decades after he created the work, along with his son, Tony.

"I was quite young. I was 9, 10, and 11. We took three years to do it," says Tony Silva. "I remember this was a pretty tough neighborhood back then. There was lots of, you know, young hoodlums and gang members around and they were kind of scary folks, but little by little they started to come around and work on the benches themselves and it made them a little less scary to see them excited about a project like this."

Pedro Silva also has fond memories of those days.

"We had a big response from the community. The way workers have involved the community into doing the artwork. I had about 3,000 people coming here — not all at once, but I had 50 and then 100 people a day," says Pedro Silva. "I had a good team of artists and helpers. They helped me run the work shop. Other people did the mosaic. I did the sculpture and than we put the mosaics over them."

The rolling bench is the best known work of public art by the organization City Arts which has coordinated the creation of nearly 270 murals around the city by children in collaboration with professional artists. The organization is celebrating it's 40th anniversary this year.

Not only are people restoring the mosaic, but they are adding to it as well.

"We would like them to feel the sense of ownership, the sense of belonging," says CityArts executive and artistic director Tsipi Ben-Haim. "Therefore they are creating their own special pictorials they feel that represents their community."

Ben-Haim says it's exciting to have some of the original team back and new volunteers from the community as well.

"They come to restore the little pieces of mosaic that were somehow thrown out of the bench or pick them back and put them where they belong or to create their own very special pictorial that talks about their own community," says Ben-Haim.

The project already has a few hundred volunteers to help, but organizers say they’re always looking for more. For details on this and other mural projects around the city go to CityArts.org.

CityArts hopes to have the restoration completed by the end of August.