While some parts of the world are instituting bikini bans and campaigning for travelers to cover up, elsewhere, travelers are encouraging others to take it off on social media for everyone to see.

What began as a spontaneous idea and Instagram post has sparked a stream of travelers to send in fun, topless photos -- taken from the back -- to be featured on the social media channels of the Topless Tour, which began as an Instagram project.

Judging from the enthusiastic response and growing number of participants, there's something about posing topless that heightens the feeling of liberation and adventure while traveling.