They dye the clothes right there in pits that have been in use for 300 years. Many of the pits have fallen into disrepair and are full of garbage, but there are still several that were full of dye.
File:Kofamata dye pits (Kano).jpg - Wikimedia Commons
Traders drink the water residue KANO STATE'S ANCIENT TIE & DYE MARKET, Nigeria TRAVEL GUIDE
The Dying Dye Pits of Kofar Mata – Kamso Kids
Indigo cloth kano nigeria hi-res stock photography and images - Alamy
Visit the Dye Pits Of Kano. Visit The Dye Pits of Kano
Dye pits and traditional dyeing activities in Kofar Mata, Kano
Why Nigeria's historic dye pits in Kano risk closure
Kamso's Journey to Kofar Mata. – Kamso Kids
5 centuries in business: Nigeria's ancient dye pits
Kofar Mata Dye Pits - Wikidata
5 centuries in business: Nigeria's ancient dye pits
Shakothelabel - Indigo tie dye process in Kano, North West Nigeria
Beloved yet banned: The surprising history of tie-dye
Dye pits kano nigeria hi-res stock photography and images - Alamy
File:Kano City Dye Pit (1).jpg - Wikipedia