A popular spot for nature lovers in the East Bay is about to vanish. A major part of the so-called "Secret Sidewalk" in the Niles Canyon has been demolished.

The Secret Sidewalk is about two miles and starts near Old Canyon Road in Fremont.

"It's unfortunate because I think it would have been nice if they would have considered turning it into a park and opening up access," said Fremont resident Michael Murphy, who lives nearby.

The Secret Sidewalk is a hot spot for hikers that is the top of the Old Springs Valley aqueduct. The property is owned by a company called Mission Clay Products that manufacturers sewer pipes.

The company told NBC Bay Area the Secret Sidewalk was a liability and needed to be removed.

"I feel bad for it. It's an artifact," said Lance King, a Niles resident. "It would be nice if they would have left or can leave just a representative section of it so people can see."

Members of the Sierra Club said old oil bunkers are also on site and previously posed a possible environmental risk for interested developers.

A spokesperson with the San Francisco Public Utilities Commission said the property owners have not contacted them about any development project, which they are required to do. However, they do know of a restoration project going on.