I came across A Broader View via social media a few years ago, and they have continuously caught my attention as setting an excellent example of a social media presence.
One thing that sets them apart from many other travel-related entities is that they post frequently on LinkedIn. Travel tends to rely heavily on visual platforms, especially Instagram and Pinterest, and, of course, Facebook and Twitter
http://maximizesocialbusiness.com/volunteer-tourism-organizations-leveraging-social-media-20593/