A holiday round Europe, with no specific plan or agenda. Normally only taken by gap year students and hippie stoner types, who have much more free time on their hands than more 'productive members of society'.
A friend of mine wrote about his travel experiences[1] whilst on a European Ramble; he was obviously inspired by some flash of creativity , as it is one of few genuinely funny thing I've ever read on The Internet.
[1] : http://www.chilled.org.uk/muppet.htm