The Cornfield was a mysterious location where Anthony Fremont would banish individuals, objects, and animals whom he disliked to. (TZ1: "It's a Good Life") The exact nature of the field was unclear.
Background information[]
Information on The Cornfield was not truly given until "It's Still a Good Life", where the nature of the place was more alluded to, but was still kept vague. Anthony claimed the place was a location where everyone was happy, and in a place where he could no longer hurt them. He could, however, never bring back anything he sent there. His daughter, Audrey Fremont, on the other hand, had the ability to bring back everything he banished.
The Cornfield was clearly not a literal cornfield, and whether or not the place was even on Earth, as it was said many times that Peaksville had either been separated from Earth, or Earth was simply gone, with no Cornfield in sight.