Plantagenate Royal Palace (site of)

The Plantagenet Royal Palace site near Rickmansworth is essentially a patch of Hertfordshire countryside where medieval royalty once held court - though you'll need a decent imagination to fill in the blanks. What remains is largely underground: earthworks, foundations, and archaeological evidence rather than standing stonework. It's the sort of place that rewards a proper history buff far more than casual visitors.

You're walking over ground where 13th and 14th-century monarchs conducted the business of ruling England. The site itself is accessible but unmarked in many stretches, so this isn't a drop-in-and-gawk sort of visit. Getting the most from it means doing your homework beforehand - knowing which king built what section, understanding the palace layout, that sort of thing. For families with restless kids, it's probably not the answer. For walkers with an interest in medieval England, though, it's genuinely atmospheric.

Access details are sparse, but the site is generally open to the public. Allow a couple of hours to properly explore without rushing. It works well as part of a longer walk around the Rickmansworth area, particularly if you're staying at one of the nearby parks like North Hill Farm or Fuzzy's Farm - both within easy distance. Combine it with a riverside walk along the Colne and you've got a solid day out that goes beyond the usual park-holiday routine.

Best visited when the vegetation isn't too thick, so spring or autumn beats summer for actually seeing the earthworks clearly.