Persistent error: The filename, directory name, or volume label syntax is incorrect

Question

I have:

log_dir = Path('C:/Users/Rose/project/log/')

But I am getting:

The system cannot find the path specified: "'\Users\Rose\project\log'"

OSError: [WinError 123] The filename, directory name, or volume label syntax is incorrect: "'C:\\Users\\Rose\\project\\log'"

What's wrong here?