This bit that sticks out appears to be holiday lodges. 
https://justlodgeholidays.com/lodges-for-rent/colchester/plumptons-farm-holiday-lodges/essex

Somewhere on the farm is also an intermittent campsite https://www.campsites.co.uk/search/campsites-in-essex/colchester/plumptons-farm-creek-campsite