Temple of Ramses III at Medinet Habu
See here for an examination of the atef crown at Medinet Habu.
NOTE: The atef crown, like other royal headgear could be depicted plain or with a variety of embellishments, such as extra uraei, cow horns, or solar discs. These various emblems are tracked separately from (but related to) the basic crown type. The basic form of the atef crown includes the central element (which appears in several variations) with paired flanking ostrich feathers.