Visited March 2014. Sya is in fact the group of mud-brick buildings located in the so called historic centre of Bobo Diulasso town, the oldest of which is considered to be from XI century (as the plate on one building states - but that is probably a local joke).

It is relatively small (around 50 structures, mainly old houses) - the most interesting of them looks to be the building in the center (this is equipped with a plate describing it as the oldest in Sya) and XIX century mosque built of clay. There is an entrance fee to Sya (1000 CFA) but they will try to force you to take a guide (unnecessary as the whole stroll will not take long). The mosque itself is regarded to be the bigest example of Sudano-Sahelian architecture in the whole coutry.