In this issue we are tasked with considering the questions that surround the concept of BORDERS and how we address it in architecture and urbanism. That is why the call for this edition invited contributors to consider this idea of BORDERS, Frontiers and Thresholds widely: tangibly, intangibly, large scale, small scale and as conceptually and intellectually as appropriate, bringing new thinking to the fields of architecture and urbanism. And, the response has been appropriately far reaching and far thinking.