There are 13 hackable CTOS towers throughout Chicago, and each of these sites are used to provide wireless connectivity for the CTOS. Each of these sites also gathers and stores information less important to the wider public. On the map, these tower sites are given the tag stating that if a player installs a backdoor virus, they can access more information on the area, such as hidden places, item collections, etc.
- River East Tower- Mad Mile
- Gold Coast Tower- Mad Mile
- Franklin Tower- Mad Mile
- Theatre Square Tower- The Loop
- South Side Campus Tower- The Loop
- Riverside Tower-The Loop
- Woodpark West Tower- The Wards
- Rossi-Fremont Tower- The Wards
- Calumet Market Tower- Brandon Docks
- Des Monts Canal Tower- Brandon Docks
- Lake Shore Tower- Brandon Docks
- Pequino Village Tower- Parker Square
- Hill Park Tower- Parker Square
- Pawnee District Tower- Pawnee
- There are actually 14 CTOS towers. The 14th tower is unlocked in a story mission early in Act III. This tower works like all the others, showing missed collectibles in Pawnee. This tower is not needed for the "Clear Signals" achievement/trophy.
- Hacking a CTOS Tower usually involves finding a creative way to scale nearby buildings and use security cameras to unlock electronic doors in order to reach the tower itself.
- Hacking all 13 CTOS Towers earns the "Clear Signals" achievement/trophy.
- Hacking the tower will reveal any nearby collectibles in the area that the tower had covered.
- CTOS Towers work similar to viewpoints in the Assassin's Creed series and radio towers in Far Cry 3, games also developed by Ubisoft.
- There is unique background music when Aiden is near a ctOS tower.
- ctOS tower are not making a return in Watch Dogs 2.