Entry No. 75 — the New York City file — filed under: ruins

Andover Mine

Dating back to before 1763, the Andover Mine was once one of New Jersey's most prolific iron mines, famously confiscated during the Revolutionary War to supply steel for George Washington's army. Under the management of Cooper and Hewitt in the mid-19th century, its high-grade ore was used to manufacture the country's first structural steel and cable wire for the Niagara Falls suspension bridge. Today, the long-abandoned site features a dramatic 70-foot-deep open pit, sealed adit portals, and overgrown waste dumps along a rocky cliffside.

The move: Take a scenic hike along the nearby Sussex Branch Trail to enjoy the local woods and view the historic markers detailing Sussex County's early industrial history from a safe distance.

📍 Before you go The historic mine workings are located on private property with active 'No Trespassing' signs, and the terrain contains highly dangerous open pits and unstable cliffs.

• 📍 Newton
• 💸 Free
• ⚡ Low-key
• 🌗 Outdoors

Where: 1 Wharton Rd, Newton, NJ 07860, USA

Hours: Added 2026-07-20 — confirm current access before you go.

Plan a visit & invite your people →

Further reading: Wikipedia

last checked: 2026-07-20