“Cities were the first Internet,” says archaeologist Monica Smith, because they were the first permanent places where strangers met in large numbers for entertainment, commerce, and romance. And the function and form of cities, she notes, have remained remarkably constant over their 6,000 years of history so far. Modern city dwellers would quickly find their way around any city in the past, given our shared architecture of broad avenues, monumental structures, and densely crowded residences. What we learn from examining the long history of cities is what makes them so freeing and empowering for humans and humanity. Density has always been crucial. So has infrastructure, skill specialization, cultural diversity, intense trade with other cities, an economy of acquiring and discarding objects, the delights of fashion and art, religious focus and political focus, intellectual ferment, and technological innovation. The digital internet has not replaced cities, nor is it likely that anything else will, Smith proposes, for the next 6,000 years. Monica L. Smith is an anthropology professor and also a professor in the Institute of the Environment and Sustainabilityat UCLA. She has done archeological fieldwork in India, Bangladesh, Madagascar, Egypt, Tunisia, Turkey, Italy, and England. Her new book is Cities: The First 6,000 Years.