There is an ancient burial ground that dates back to the 1700s in Steelmanville, Egg Harbor Township, Atlantic County, New Jersey. Many "Steelmans" are thought to be buried in it. It is possible that others who lived in the area are also buried in it, if their graves are not found in Zion United Methodist Cemetery on Zion Road in Egg Harbor Township, Atlantic County, New Jersey, and if they died before about the 1850s. The burial ground did not have any known markers. It is possible that in the 1700s, the graves once may have had wooden markers. There is no list of who was buried in it. The original families that lived in this area were mainly the Steelman, Blackman, and Jeffryes families, and some other families also lived in the area. As of now, there is nothing there to see. The burial ground is on private property and not to be trespassed. You cannot tell from above ground that it was once a burial ground. Through a process of going through both the Gloucester and Atlantic County Deed Books to verify where people lived, and then by checking to see if those people are in Zion UMC, it becomes apparent that if they are not buried in Zion UMC, and they died before the 1850s, they are likely buried in this ancient burial ground, if their properties bordered the old burial ground. The following 2 deeds mention the location of this ancient burial ground in Steelmanville:

16 AUG 1833: John W. Jeffryes, Sr., conveys land to Andrew Ketchum (who was his son-in-law and first husband of his daughter Judith Jeffryes). Both parties of Egg Harbor Township, Gloucester County, NJ (before 1837, this area was a part of Gloucester County; now it is a part of Atlantic County). This deed mentions the "Burying Ground" and 1/2 acre sold for a school house lot. Gloucester County Deed Book H3, page 352, etc. Link: https://www.familysearch.org/ark:/61903/3:1:3Q9M-CSGD-73K7-T

The next deed is in Atlantic County Deed Book 71, page 444, etc.:
28 AUG 1878: The Grantor is William Lake, and he was the executor of the deceased Peter Steelman of Steelmanville, Egg Harbor Township. Peter was married to Lydia. Per Peter's will dated 30 SEP 1876, he ordered William Lake his executor to sell his land. The grantee is Brazier Booye. The land being sold is in Egg Harbor Township: "...Beginning in the center of a small creek that empties into Patcong Creek just below what is called Jeffries Landing and at the NORTHEAST corner of Larner Steelman's lot and runs in his line south...(many measurements)... also a corner to Evin Jeffries' line (that is Evin Jeffries, the son of Evan Jeffryes, Sr., and Sarah "Sallie" Young, and grandson of John W. Jeffryes and Judith Steelman. Evin was married to Hannah Risley, the daughter of Samuel Risley and Mary "Polly" Stebbins, and granddaughter of Nathaniel Risley and Sarah Steelman, and great-grandaughter of Peter Steelman (c.1731-c.1775), who's land this area used to belong to - he was son of James Steelman and 2nd wife Katherine Ouster). Many more measurements listed... to a cedar stump in Samuel Sampson's line and said to be the stump of a tree called for in the deed from John Jeffryes to Peter Steelman dated 29 AUG 1836... to a corner by Larner Steelman and Andrew Booye to stand in the old line of John Jeffryes and Steelman also at the west corner of the "old graveyard" thence in what is called the old Jeffryes line... to a stone in the center of the road that leads from Joseph Scull's to Bargaintown... then north, then east... in a line of the Friendship Methodist Protestant Church...more measurements... to a line of 10 acres willed by said Peter Steelman to his sister Hannah Haines/Harris... more measurements/more names listed....
LINK: https://www.familysearch.org/ark:/61903/3:1:3Q9M-C37Y-LTV4

Of note, in this area, Ocean Heights Avenue used to be called "Neck Road." The church mentioned above used to be on Steelmanville Road, but was later moved to Ocean Heights Avenue.

1872 Map of the area: (Steelmanville is down by where it says "Cedar Swamp Creek"): Map available on Library of Congress's website. This link may or may not work:
https://www.loc.gov/resource/g3813a.la000437/
On the map, the "Jeffries/Jeffryes" surname is spelled as "Jeffers." The map shows Evin Jeffries, and Larner Steelman, and the school, and many other familiar names of this area.