RE O155 Circular Boating Route:  The Green and Silver Route is 356 km long with a total of 93 locks.  It is a spectacular boating experience through urban and rural waterways  commemorating an original journey made back in 1946.  The engineering challenges faced by the builders of the Grand and Royal Canals over 220 years ago is striking; they built aqueducts, lifting and swivel bridges, single and double locks, harbours and succeeded in creating canals through the bog.