Like many other cities Rotterdam has adopted the circle strategy to ‘nudge’ people into keeping an appropriate coronaproof distance in public parks. The circles were first applied in Domino Park in Brooklyn N.Y. and soon went viral, mutating along the way, with variations in size, spacing and pattern.
But when gathering like this, whether it is in a public park or on the beach, After Corona or Before (AC or BC), people tend to keep their distance in public space instinctively, guarding their personal space. The social circle strategy is a ludic form of crowd control but the crowd knows perfectly how to control itself, as demonstrated in the picture below.