For months, drug buyers made a daily pilgrimage to a single street in Zefyri, a western Athens suburb long seen as one of the capital's most lawless pockets.
They headed for 12 homes ringed by high walls, razor wire and surveillance cameras.
Now police say they have dismantled the network behind it. Officers arrested 36 people in a dawn raid on Saturday, authorities said this week.
Many of those arrested belong to the same extended families.
The raid matters beyond its size.
Zefyri and neighboring districts have for years been tied to drug dealing, armed clashes and stolen vehicles, often in areas where police rarely ventured.
The government has made restoring order there a priority. The operation involved elite counterterrorism officers and a drone.
Investigators documented 396 drug sales.
They said the homes operated like fortresses, with security doors, iron gates and barred windows. Lookouts watched the street around the clock, and drugs were stashed in nearby empty lots.
Each house was run by its own crew.
When police stopped 24 buyers leaving the homes, every one of them was carrying drugs.
The suspects span three generations.
They include a 43-year-old woman and three of her children, among them a heavily pregnant daughter who was taken to the hospital.
A 66-year-old woman and her two adult daughters were also detained.
Officers seized heroin, cocaine and an unidentified white powder, together amounting to less than a quarter of a kilogram.
They also found motorcycles with filed-off serial numbers and handwritten ledgers recording names and small debts.
The small amount of drugs points to a business built on many small sales, the kind of neighborhood trade that has proved hard for Greek authorities to root out.
The investigation began in late May with tips about dealers and their phone numbers. Wiretaps followed.
All 36 suspects were brought before a prosecutor.
By Katia Niakari