I thought now that I have such cool looking sewers (Bettys Sewer Textures) I have nothing to do there.
So I made a little cache hunt quest for that place. It will make you search for lost items in the Imperial-Sewers.
It might be a simple quest, but the items are well hidden sometimes. Be warned :D

To start the quest, find NPC Little-Scale in the Arboretum-District.

Ignore the image, I just needed to display something :)
The items are nothing special and can be confused with other look-alike items, but the name-tag on it will be very obvious.

Spoiler:  Show
Talos Plaza   1
North2        3
Elven Gardens 1
South East    2
North1        2
South West    1