Culturally, korzo is the regular evening procession of walkers on the main street promenade. Ours had five columns - those standing with their back to the shop windows, then those going up the street, then those standing in the middle, then those going down the street, then those with their backs to the street. So no matter where you are, standing or walking, you get to see everybody who's there - either of the three standing columns, or the rest of the moving one. You can step in or out at any time - spot someone you know, in company of someone you don't, maybe get acquainted on the spot. Most of the evenings this used to involve a few hundred people, perhaps a thousand.
It was a perfect mechanism to see and be seen, to meet people, to gather company to go somewhere afterwards. You'd come to the korzo to see who's there. Now you could walk a round or two, specially if you had company, and you'd see anyone in the standing columns, and possibly some from the opposite walking column. By the second round, you had company for the evening, or just decided to join one of the standing columns and talk with someone, and then a third and fourth person would show up. Usually an evening out would begin with an hour on the korzo, usually between 19:00 and 20:00, and then the decision where to go was made on the spot. Sometimes all who gathered would go together, sometimes they'd split and go to two places, or some would simply go home.
The tradition began who knows when, a century or two ago. It stopped in the nineties, when a string of cafes opened in the two backstreets surrounding the main street (as they couldn't get spots in the street itself). That shifted the center of gravity. Then some of the cafes died off, but the korzo didn't return. The main street gradually began the pedestrian zone - first in the evenings only, starting in late seventies, then permanently, and the move of the bus stops about 200m away dragged even more people away. Then after 2000 the general shift of regular shops away and the enforcement of more expensive boutiques, exchange offices, cell phone operators, banks, more banks and cafes onto the main street caused even less foot traffic, so not only was there not even a shadow of the once korzo, it's practically deserted. In the evening, at all times, you can see the shop windows on the other side, which used to be unthinkable.
We've seen korzo still alive and kicking in other places - Požarevac 2012, Užice 2018. In Požarevac they had the folks gyrating in a wide circle around a monument in the middle, and everything else was in freeform motion.
Here in the city the cafés have moved over to the main street, once the pavement was flattened wall to wall, in 2007 and partially before, they'd have their tables out march-october, some years even beyond that, weather permitting. Some of them are operating from the top floors of main street houses, so waiters walk a lot on the stairs. Their tables take up the space of the former traffic lanes. Yet the korzo hasn't returned, because there's a cell phone now. The old "I'm off to town to see who's there" implied "then we'll see where we'll go". Now they already know who and where, they set it up in advance, they'll meet there and then.