It's the very definition of a 'forever' home - even if the world as we know it abruptly ends one day.

A historic colonial home in Washington, New Jersey, has been sold for more than $400,000, but it's a feature under the house that's sparked intrigue.

The three-bedroom, two-bathroom home not only sits on half an acre of land, but also features a doomsday prepper bunker.

'Totally unexpected, this Historic Colonial is also a Prepper Home with an Underground Bunker! Transformed Historic Colonial,' the listing enthusiastically reads.

A historic colonial home (pictured) in Washington, New Jersey, has hit the market - but it's what's under the house that's sparked intrigue

The three-bedroom, two-bathroom home not only sits on half an acre of land, but also features a doomsday prepper bunker

The spacious home, which sold just last week for $405,000, as per Zillow, covers 1,229 square feet, and boasts three bedrooms and one-and-a-half baths. 

But those aren't the amenities that set the historic home apart.

Behind a shiny new deck that overlooks the private backyard is perhaps the best - and most hidden - feature of all: an aluminum shed with a hatch to an underground bunker or panic room.

The backyard also features a full-size shed or workshop.

The first floor of the house is designed for 'living and entertaining.'

'It offers an eat-in kitchen equipped with stainless steel appliances, including a microwave, electric range, and dishwasher,' the listing continued.

'The living room, anchored by a wood-burning stove, provides a cozy atmosphere and ample space for a dining area.'

Also on the first floor is a family living room and sunroom, as well as a mudroom, laundry room and bathroom. 

'The journey through the home culminates in stairs leading to a vast unfinished attic,' the listing boasts

Despite being built in the 1830s, parts of the home remain unfinished and a blank slate for the next homeowner

The listing admitted the additional bunker was 'totally unexpected'

The first floor offers an eat-in kitchen (left) equipped with stainless steel appliances, including a microwave, electric range, and dishwasher. Pictured right is a living area

The deck overlooks a private backyard with an old stone small out-house type building

The bunker is accessible by a trapdoor located within the shed in the backyard

Urging future owners to make the most of the space, the listing describes the space as 'expansive'

There are three bedrooms on the second floor, everyone with their own closet space.

The primary bedroom - which the listing describes as 'a retreat within the retreat' - has a half bathroom attached.

Despite being built in the 1830s, parts of the home remain unfinished and a blank slate for the next homeowner.

'The journey through the home culminates in stairs leading to a vast unfinished attic,' the listing boasts.

Urging future owners to make the most of the space, the listing describes the space as 'expansive.'

'This [space] brims with potential, offering endless possibilities for customization and use, limited only by the imagination,' it read.

The home last sold in 2003 for $184,000.