Please check the location availability report to see if you can identify where the location is being used. 
  1. Click Events > Locations
  2. Click Location Availability on the left side of the page
  3. Check the box for the location 
  4. In the Availability drop-down select Unavailable
  5. Choose Specific Dates in the date drop-down
  6. Add a wide date range (several years)
  7. Click Apply

If you cannot identify where the location is being used, chat with support with the following information:   
  • The exact name of the location