Oaxaca, Mexico - the big one in Oaxaca Saturday morning, of course - but there are several in the vicinity, highlighting different crafts and items. Also Mixtec and Zapotec archaeological sites, villages with different crafts specialties (Teotitlán del Valle, wonderfu woolen weavings and clothes; Tlacolula and San Bartolo Coyotepéc, potterty, etc. etc.) From planeta.com

MARKET DAYS
Domingo/Sunday:
Tlacolula (perhaps the oldest in the Americas)
Nochixtlan

Lunes/Monday:
Ixtlán
Miahuatlan
Villa Alta

Martes/Tuesday:
Atzompa or Santa Maria de Atzompa (nearby, famous green pottery)
Ayaquezco de Aldama

Miercoles/Wednesday:
Zimatlán
San Pablo Etla

Jueves/Thursday:
Zaachila
Ejutla

Viernes/Friday:
Ocotlán (ceramics)

Sabado/Saturday:
Tlaxiaco
Mercados de Oaxaca