In his book The Art of Travel Alain de Botton describes the "sublime" as those things which display a great power, a power greater than that of humans. The word is intended to be used to describe things which emphasise the smallness of humanity in comparison to the power and wonder of nature. Most commonly this meant heroic landscapes such as mountains, gorges, deserts etc.
I've been fortunate enough to have my own experience of the sublime, most strongly when I was being driven through the Norwegian fjords, weaving around gigantic barren snow-capped mountains. Unlike the rolling pastures of England, it is a landscape which seems brutally indifferent to human existence.
Being in the metropolis has also aroused a similar feeling in me. Although this strays from the above definition of the sublime by describing an experience of something human-made, I believe the feeling can be just as powerful. An example from my own experience is my encounter with Manhattan. Wandering among the giant buildings, their size beyond the immediate comprehension of a pedestrian I felt enclosed by mountains. At other times the views down the streets brought to mind endless canyons. Immediately I felt small and insignificant compared to phenomenon that is New York City. It wasn't an unpleasant feeling but an awe inspiring and humbling one.
Other examples could include the experience of being in Sao Paolo or Hong Kong.
Do these settings arouse the sublime only because they remind us of natural phenomena which could more readily be described as such? I believe that's part of it. But I also believe that such experiences of extreme urbanity place us in a situation where we face the reality of incomprehensible human abundance and are our place in it. Society suddenly feels very big and we can feel very small.
Among the skyscrapers and heaving masses we feel insignificant, but I would also say that we feel liberated knowing that our own worries and problems are just a small number among millions of others. Although own particular problems may seem personal to us, chances are, out there, many others have gone, are going or will go through the same.
Although it may not be quite the same as the natural sublime, the urban sublime has its own atttraction and is worthy of our attention.