Shalebridge was a district of the City located near the Old Quarter and Wayside. One of Warden Raputo's districts,  it is located along a shallow point in the River that can be waded across in times of severe drought. One of the main access roads from Wayside is Shalebridge Road and it is famously the home to the abandoned Shalebridge Cradle.
The district is first mentioned in the T1/TG mission, "Assassins", but does not appear on a map until the T2 mission "OM T2 Ambush!", where, after an ambush at the Crippled Burrick Pub, and the watch knowing his apartment location, Garrett moves and sets up a safe house in Shalebridge.  In an earlier mission, Garrett had a parcel redelivered to a fence in Taft Avenue, Shalebridge.
While both T1/TG and T2 treat Shalebridge as a district of the City, TDS, which scales down the size of the city greatly, has it as a very small area of the Old Quarter, near the Bridge to Auldale.
- Shale is a kind of fine-grained sedimentary rock which is composed of mud, clay, and small fragments of other minerals. It is the most common of all sedimentary rocks and as it is fairly fragile, it is rarely used for building.. So making a bridge out of it would probably be a bad idea)
- Due to the areas overseen by Raputo, it's possible that Shalebridge is also near North Quarter, New Quarter or Newmarket as well. Most likely Newmarket, which is near the Old Quarter.