Police found 593 marijuana plants growing inside a five-story building near the Bronx Zoo on Tuesday and arrested three Bronx men for running a massive drug ring.

The suspects — 24-year-old Brian Munoz, 25-year-old Diego Reyes and 23-year-old Victor Reyes — were charged with criminal possession of marijuana and criminal use of drug paraphernalia.

Authorities say the three suspects ran a "sophisticated operation" that took up all five floors at 610 Morris Park Avenue, and the building had a watering system, electrical system, carbon dioxide system and a ventilation system to help the high-grade marijuana grow.

There were also 75 pounds of cut, dried and packaged marijuana found in the building.

Some of the marijuana plants reached a height of 7 feet, and all the confiscated plants' yield would have had a street value of at least $8 million.

Together, the dried marijuana and plants weighed about 1,550 pounds.

Police estimate that the three suspects made at least $3 million in drug sales last year.

While some neighbors told NY1 they did not realize a large drug operation was taking place in the area, but others suspected something was afoot.

"I've been here for eight years and never did I ever smell this. This is crazy," said a local.

"It's surprising that I didn't know something like this was going on," said another.

"I smelled it all the time, I live right on Fillmore [Street]. It's crazy," said a third.

After receiving community complaints and conducting a two-month investigation, police finally got a search warrant for the location on Tuesday.