I've been visiting the barn each summer for almost a decade, 'camping' with friends. Though it was rather basic for the first few occasions (emptying the toilet wasn't fun), now there's a gas cooker and lighting inside, more kitchen utensils than one could need, water for washing, a 'proper' toilet, and bunks have been installed on the upper storey. At the time of writing, it costs £40/night (£90 Fri-Sunday), and sleeps 16, though more can be accommodated in tents, (theoretically) at extra cost. The river is only 3-4 m away, between the barn and the trees on the left of the image, with a pool suitable for cooling beer (until it escapes...).
Weather permitting, 75% of everyone's time seems to be spent sitting or lying around the open fire outside.