Sybil’s Cave Today and Yesterday
Sybil’s Cave is the oldest manmade structure in Hoboken, created in 1832 by the Stevens Family as a folly on their property that contained a natural spring. By the mid-19th century the cave was a recreational destination within walking distance from downtown Hoboken. A restaurant offered outdoor refreshments beside the cave. When the Stevens’ family property became Stevens Institute, the cave became property “of the Institute and periodically opened to the public in the early 20th century. By the late 20th century the building had been covered in building debris.
Take an interactive virtual tour of the cave by clicking here or on the image below. 
The page with the panorama includes a Google map.
In 2007 the cave was rediscovered and cleared by the City of Hoboken. With limited research, the City erected a new cast stone arch and fence that marks the cave, but prevents entry.
The Hoboken Historical Museum received a grant in 2009 from the New Jersey Historic Trust for a geo-ecological plan for mitigating the environmental changes caused by the recent opening of the cave and developed a plan for an appropriate use of the Cave and interpretive programming. A comprehensive archeological excavation was performed of the interior to learn as much as possible from the site with the least intervention but with careful attention to the site’s integrity. An engineering firm was engaged to establish the safety of the Cave’s structural integrity and the quality of the spring water.
Two documents were created from these investigations:
Geotechnical Condition and Water Quality Analysis for Sybil’s Cave. (Black & Veatch, January 2011); Appendix: Detailed Water Quality Sample Results.
Archaeological Assessment, Sybil’s Cave, Frank Sinatra Drive, City of Hoboken, Hudson County, New Jersey (Richard Grubb & Associates, May 2012)
Text of these documents may be read in full in this article, or you can click on one of the document page images to see the entire document including illustrations and tables.
Appendix: Detailed Water Quality Sample Results.
On the next two pages you will find the text of these documents; to see the illustrations and documentary materials use the links on document images above or at the top of each of following pages.