the intentional slurring together of the English words forget + about + it toward the effect of expressing surety, wonder or degree of approval; the usage is largely associated with New York soldiers of the mafia.
The physical space where you forgot why you left one room to go to another room to get whatever it was you wanted, sometimes forcing you to go back to the first room. Maybe several times.
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2million.