Koufonissia comprise two isles, Ano (Epano or Apano) and Kato Koufonissi (5.7sq.km. and 4.4sq.km. respectively), which are separated by a narrow strait 200m wide and the island of Keros. Kato Koufonissi is virtually deserted, but has a small port and numerous small and isolated beaches. Keros was as prominent during the period of the early Cycladic civilization as Delos was during Classical antiquity.