[Lord Elrond]

I just thought I would add that most great structures (Orthanc included) were built by the men of Westerneese long ago. Orthanc, the Morannon, Minas Ithil(morgul), even Cirith Ungol, as well as many smaller fortresses on the mountains of shadow. But yes it does look like a more wholesome version or lighter version of Orthanc.