I know this one has been done to death, but I managed to see it for the first time last month, and i'm posting in the hope that people are still interesed in how the place is changing with the current works that are going on. The arches are now home to a huge support for the new brige that has been put in across the river Irwell, and workmen are in the Arches on a daily basis, with much of their lighting equiptment left in 'situ'
History taken from, and as usual, more available from here:
http://en.wikipedia.org/wiki/Victoria_Arches
The Victoria Arches were a series of arches built in the embankment of the River Irwell in Manchester. They served as business premises, landing stages for Steam packet riverboats, and also as World War II air-raid shelters. They were accessed from wooden staircases which descended from Victoria Street. Regular flooding of the river resulted in the closure of the steam-packet services in the early 20th century, and the arches were used for general storage. In World War II the arches were converted for use as air raid shelters.