Parks Department workers found a large stash of heroin that had been abandoned under a pile of brush at a Bronx park, authorities said.

The workers stumbled on the drugs, which were packaged in more than 500 individually wrapped glassine envelopes, while working in University Woods Park around 10:30 a.m. Sunday.

The heroin was buried under a pile of rice, which was intended to keep moisture out. The rice had then been covered with leaves and sticks.

The workers also found two cellphones and a box cutter under the brush.

The narcotics were turned over to police, who are working to determine who left the stash, cops said.