Dating from about AD 1000, Quilmes was a complex indigenous urban settlement that occupied about 30 hectares and housed as many as 5000 people. The inhabitants survived contact with the Inca, which occurred from about AD 1480 onward, but could not outlast the seige of the Spanish, who in 1667 deported the remaining 2000 to Buenos Aires.
Quilmes’ thick walls underscore its defensive purpose, but clearly this was more than just a pucará (walled city). Dense construction radiates from the central nucleus. For revealing views of the extent of the ruins, climb as high as you can; there are trails on either side up to the remains of the watchtower. Be prepared for intense sun with no shade, and, during the hot summer months, a large fly population keen on exploring your facial orifices. Guides at the entrance will offer an explanation and/or tour for a tip. Don't expect accurate archaeological analysis.
The long defunct museum was finally under renovation at the time of research, with an opening date in early 2018 being spoken of in hushed tones. This will be a good thing, as it's difficult to interpret the ruins without some solid reference at the site. Friendly folk selling local ceramics also have cold drinks to buy. There are no lodging options and no camping is allowed at the ruins, and nightlife at Quilmes belongs to the wildlife and the ghosts.
Buses between Cafayate and Santa María or Tafí will drop you off at the junction; from there it’s a 5km walk or hitchhike to the ruins. Alternatively, get off at Amaicha del Valle, where a remise (taxi) will charge around AR$200 one way to the ruins: bargain to get a decent price, including waiting time. A remise from Cafayate or Santa María is also an option and tours run from Cafayate and Tafí.