MANCHESTER TOWNSHIP — A Union County man drowned Saturday in a body of water dubbed "Crystal Lake" at a sprawling privately-owned former mining site that has been the site of other drownings, township police said.

Edwin Caballero, of Plainfield, visited the Heritage Mineral property that spans 7,000 acres on Saturday afternoon, according to Manchester Township Police Capt. Todd Malland.

The 23-year-old Caballero went missing between 5 p.m. and 6 p.m., his family said to police, and after they couldn't find him they called first responders, who arrived and began to search around 10 p.m.

Caballero’s body was recovered Sunday morning by members of the State Police Technical Emergency and Mission Specialists (T.E.A.M.S.) unit. Malland said upon initial investigation,
the death appeared to be an accidental drowning.

Despite being dubbed a "lake" by locals, the groundwater aquifer is one of many such "blue holes" left behind by years of mining around New Jersey, that appear inviting on the surface while being fraught with hazardous conditions.

Unstable sand and shoreline shelves that plummet unpredictably to depths of more than 60 feet, and notably cold water temperatures from a deep underground source pose dangers that have led to such tragedy before.

The Ocean County property was the site of the 2015 drowning death of 17-year-old township resident DeNasia Davis, as reported by Patch Manchester.

Just days apart the same summer, a different 17-year-old died while swimming in a similar blue hole in the Pinelands of Monroe Township, Gloucester County, as reported by NJ.com.

Manchester Police reiterated this weekend that the Heritage Minerals or “ASARCO” (American Smelting and Refining Company) site is private property, closed to recreational or other use, under penalty of hefty fines or jail time for trespassers.

The serene-looking property periodically inspires drone or scenery videos, such as one posted to Youtube in 2015 by dcvmnaturalist:

Anyone else at the site Saturday who might have seen what happened can contact Manchester Township Police at 732-657-2009 ext. 4221 or the Ocean County Prosecutor's Office Major Crimes Unit at 732-929-2027.

More from New Jersey 101.5: