Today, with the opening up of new frontiers for human activity, almost every corner of the earth has been visited by the footsteps of man, with the exception of the far reaches of space. Add the surge in tourism, and it's impossible to discover still unknown places.
今日，隨著人類活動範圍的拓展，除了外太空和內太空外，地球幾乎所有的角落都已烙上人類足跡，加之旅行風潮的盛行，探索未知的地域幾已不可能。