I found this from a Springwise mailing - It's Rambler [www.ramblerhq.com] which provides all sorts of options and ideas [some oddball] to enliven travel.  Given the demographic of the source [you have to sign in via Facebook] many if not most are geared to the 20's-30's age group, but there wasn't anything particularly agist about some of the suggestions, just not something we would all do.  But it's a fun way to get beyond the usual tourist haunts.