We recently went "glamping" (glamorous camping, in case you're not familiar with it) and I reserved a travel cot with the intention of using it as a playpen because the trouble with tents (however "glam") is that they don't lock. And keeping a 2-year-old contained is really hard work! And Joe was perfectly happy in his playpen, as long as he had something in there to keep him entertained.
I think the playpen pictured is rather lovely. It's from Mothercare and can currently be found on Nappy Valley for £50. And if that one's not your style, there are plenty more.