Thursday Challenge—patterns

This pattern set into the pavement of the
Piazza San Marco, in Venice, seems slightly
off-kilter.  I don't know why that is—but you
might not even notice it at all unless
you go up in the campanile and look down.
(They were experiencing some aqua alta  in 
November two years ago.  The circles
in the pattern are drains, but they won't 
do their job until the tide goes out.)

[To see more of the Thursday Photo Challenge, go here.]