Exceptionally rare opportunity to acquire a Cold War-era underground communications facility, originally constructed between 1967 and 1971 as part of AT&T’s Long Lines network and engineered for durability, redundancy, and long-term self-sufficiency. The property features an approximately 4,813-square-foot below-grade reinforced concrete bunker beneath a 987-square-foot, four-car concrete block garage. The bunker is configured with multiple secured rooms, hardened corridors, mechanical and utility areas, a generator room, decontamination room, full kitchen, and four bathrooms. An elevator connects the above-grade garage to the underground facility, while copper screening within several interior partitions provides additional electromagnetic attenuation. The facility underwent extensive renovations in the early 2000s to support its potential use as a secure data and communications center. These improvements included updates to the electrical distribution, mechanical systems, and interior spaces for sensitive equipment and long-duration operations. Power infrastructure includes commercial electric service with automatic transfer capability and a 150 kVA diesel generator supported by approximately 2,500 gallons of on-site fuel storage. Heating and cooling are provided by multiple geothermal heat pumps served by four reported geothermal wells approximately 300 feet deep. Water infrastructure includes a separate potable well reported to be approximately 125 feet deep, a 1,500-gallon fresh-water storage tank, water filtration, and an on-site septic system. The facility also incorporates multi-stage air filtration designed to support extended below-grade occupancy. Situated on approximately 9.17 private acres, the property features a high gated perimeter fence, controlled entrance, substantial setbacks, and a discreet, low-profile footprint. The property is located in Flood Zone X and is currently zoned Agricultural Preservation. The existing commercial use has been identified in the appraisal as a pre-existing grandfathered use. Potential applications include a secure private compound, data center or server facility, continuity-of-operations site, research facility, specialized storage, or other approved uses. Due to the unique and sensitive nature of the property, certain information is available only to qualified prospective purchasers. Showings by appointment only. Proof of funds required. All proposed uses, system capacities, operating conditions, zoning, and measurements should be independently verified.
For sale
$999,999
410 Hassenplug Rd, Millmont, PA 17845
4beds
5,800sqft
Single Family Residence
Built in 1969
9.17 Acres Lot
$-- Zestimate®
$172/sqft
$-- HOA
What's special
Multiple secured roomsGenerator roomControlled entranceDiscreet low-profile footprintFull kitchenDecontamination roomHigh gated perimeter fence
- 4 days
- 622
- 58
Zillow last checked:
Listing updated:
Listed by:
Blain Berrier 717-645-6418,
RSR, REALTORS, LLC (717) 763-1212,
Co-Listing Agent: Jeff Koury 717-439-2047,
RSR, REALTORS, LLC
Source: Bright MLS,MLS#: PAUN2000880
Facts & features
Interior
Bedrooms & bathrooms
- Bedrooms: 4
- Bathrooms: 4
- Full bathrooms: 4
Basement
- Area: 4813
Heating
- Heat Pump, Geothermal
Cooling
- Geothermal
Appliances
- Included: Electric Water Heater
Features
- Air Filter System, Attic, Double/Dual Staircase, Recessed Lighting
- Basement: Finished
- Has fireplace: No
Interior area
- Total structure area: 5,800
- Total interior livable area: 5,800 sqft
- Finished area above ground: 987
- Finished area below ground: 4,813
Property
Parking
- Total spaces: 3
- Parking features: Garage Faces Front, Oversized, Attached, Parking Lot
- Attached garage spaces: 3
Accessibility
- Accessibility features: None
Features
- Levels: Two
- Stories: 2
- Pool features: None
- Has spa: Yes
- Spa features: Bath
- Fencing: Barbed Wire,Chain Link
- Has view: Yes
- View description: Mountain(s)
Lot
- Size: 9.17 Acres
- Features: Backs to Trees, Hunting Available, Wooded, Private, Secluded, Rural
Details
- Additional structures: Above Grade, Below Grade
- Parcel number: 005005987
- Zoning: COMMERCIAL
- Special conditions: Standard
- Other equipment: Intercom
Construction
Type & style
- Home type: SingleFamily
- Architectural style: Other
- Property subtype: Single Family Residence
Materials
- Concrete
- Foundation: Concrete Perimeter
Condition
- New construction: No
- Year built: 1969
- Major remodel year: 2002
Utilities & green energy
- Electric: 200+ Amp Service
- Sewer: On Site Septic
- Water: Well
Community & HOA
Community
- Security: Main Entrance Lock, Motion Detectors, Security Gate, Security System
- Subdivision: None Available
HOA
- Has HOA: No
Location
- Region: Millmont
- Municipality: HARTLEY TWP
Financial & listing details
- Price per square foot: $172/sqft
- Tax assessed value: $224,800
- Annual tax amount: $4,804
- Date on market: 9/7/2026
- Listing agreement: Exclusive Right To Sell
- Listing terms: Cash,Conventional,Bank Portfolio,Joint Venture
- Ownership: Fee Simple
Estimated market value
Not available
Estimated sales range
Not available
Not available
Price history
| Date | Event | Price |
|---|---|---|
| 9/7/2026 | Listed for sale | $999,999$172/sqft |
Source: | ||
Public tax history
Tax history is unavailable.
Monthly payment
Est. payment
Payment breakdown
Explore the cost of this home by adjusting the details. Changes won't be saved.Climate risks
Neighborhood: 17845
Nearby schools
Schools provided by the listing agent
- District: Mifflinburg Area
Source: Bright MLS. This data may not be complete. We recommend contacting the local school district to confirm school assignments for this home.




