The Ochus is a river, today-called Darya-i Pandj, which flows in modern Tajikistan and joins the Amou-Darya at the level of Takht-i Sangin. In Ancient Times it flew in the northern part of Bactria and joined the Oxus at the lvel of the town called Oxeiana (which was not Alexandreia Oxeiana).
The famous site of Aï Khanoum is located on the Ochus; until 2002 a general misunderstanding among historians was to make the Ochus the eastern part of the Oxus, and not one of its tributaries, which had several consequences on the allocation of ancient towns' names in the area, especially for Aï Khanoum.
