KTEO (vehicle technical inspection centre)
The centre where a vehicle's periodic technical inspection is carried out. Inspections are compulsory at intervals that depend on the vehicle's age and type.
At the KTEO the vehicle's brakes, lights, emissions and general condition are checked, among other things.
Your next inspection date is shown on your vehicle documents. Book before it expires, because a late inspection can lead to a fine.
Official source: gov.gr (Greek government portal)