The Remenham Barrier

Standing where the River Thames bends sharply near Remenham, this earthwork barrier marks one of the more obscure chapters in English civil defence history. Built during the Second World War as part of the GHQ Line, it was designed to slow German advances inland from the coast. What you'll find today are the remnants of concrete anti-tank blocks and earthworks, partially overgrown but still clearly visible to anyone who knows what they're looking for.

History buffs will appreciate the strategic thinking behind its placement - the Thames here creates a natural bottleneck that military planners exploited. The barrier stretches across the narrowest point, though much of it has been reclaimed by nature over the decades.

It's hardly a major attraction, more of a curiosity for those already exploring the Henley-on-Thames area. You'll need about twenty minutes to walk the length and take it all in, assuming you can access it - the site isn't officially managed and paths can be muddy.

Families staying at nearby sites like Swiss Farm or Henley Four Oaks might combine it with a riverside walk, though younger children will likely find it dull. The real appeal lies in standing somewhere that played a small but genuine role in Britain's wartime preparations, even if those defences were never tested.