Plainsfield Camp (or Park Plantation or Cockercombe Castle) is a possible Iron Age earthwork on the Quantock Hills near Aisholt in Somerset, England.

[2] The so-called hill fort has several features that make it more likely to be an animal enclosure than a defended settlement: The case for an enclosure is less clear cut than for Trendle Ring, since Plainsfield is on a spur and does have steep slopes on two sides, making it like a promontory fort, similar to nearby Ruborough.

[3] Hill forts developed in the Late Bronze and Early Iron Age, roughly during the start of the first millennium BC.

[5] Archaeologist Barry Cunliffe believes that population increase still played a role and has stated that "[the forts] provided defensive possibilities for the community at those times when the stress [of an increasing population] burst out into open warfare.

They would be functional as defensive strongholds when there were tensions and undoubtedly some of them were attacked and destroyed, but this was not the only, or even the most significant, factor in their construction".