Our world has innumerable boundaries, ranging from the obvious - like oceans and mountain ranges - to the intangible - like subtle differences in language or climate. Most of us cross invisible lines all the time, but rarely do we stop to consider them. 'Invisible Lines' presents 30 such unseen boundaries, intriguing and unexpected examples of the myriad ways in which we collectively engage with and experience the world. From football fans in Buenos Aires to air quality in China, Paris' banlieues to sub-Saharan Africa's Malaria Belt, the invisible boundaries that shape our experiences and existence provide a compelling guide to seeing and understanding our world anew.