A 24x24 Ribbon Tour

This tour solves the same task as on the 18x18 case published previously, but proved much more difficult to achieve. Given the diagonal braids shown in blue, and putting in the natural connections in each 6x6 area, similar to the 6x6 tour with the same diagonal pattern, results in a pseudotour of twelve separate circuits (4 of 14 cells, 4 of 20, 4 of 60 and 2 of 100, giving the total 576 = 24x24). 

The task is then to put in the minimum number of links to join the circuits up into a single tour and to ensure that it is a symmetric tour, which on this size of board means 180 degree rotational symmetry (which I call rotary symmetry). This is tricky since some of the circuits are themselves symmetric.