The snippets describe Cherry Green Trees as located in Colney Heath, Hertfordshire — not on Ellen Brook in the United Kingdom as specified.

However, since the location detail "on Ellen Brook" may simply be additional context and the POI name and country match, I'll note that the snippets do not mention Ellen Brook at all and the site appears to be a Girl Guiding Association (GGA) campsite near St Albans.

Cherry Green Trees is a private campsite located on Roestock Lane in Colney Heath, near St Albans, Hertfordshire. The site operates as a bookings-only facility, with reservations made by email through a booking secretary.

It is primarily associated with Girl Guiding Association members, though it accommodates other groups as well.

The site sits within Ordnance Survey Sheet 166 (Grid Reference 210 067) and is accessible from the South Mimms roundabout via Swanland Road and Tollgate Road.

A caretaker is present to manage arrivals and departures, and weekend stays are typically arranged from Friday afternoon through Sunday evening.