A new "closed" refugee camp opened on Saturday on the Greek island of Samos.
The camp is fenced with barbed wire and equipped with surveillance cameras, X-ray scanners and magnetic doors.
It also has a prison camp and is only accessible via an electronic chip.
The gates remain closed overnight.
The camp on Samos is one of five planned camps of this type on the Aegean islands of Leros, Lesbos, Kos, Chios and Samos.
The EU has made available 276 million euros for this.
The camp on Samos is intended to serve as a pilot project for the refugee camps on the other islands.
Human rights groups criticize the new "closed" refugee camps.
The restrictions on migrants are too high.
In the run-up to the opening, numerous non-governmental organizations and representatives of civil society had asked the EU and Greece to drop plans to restrict the freedom of movement of refugees.
The UN refugee agency UNHCR also expressed concern.
The Greek government, on the other hand, points to better equipment in the camps, for example with running water, toilets, separate areas for families and greater security.
Previous facilities were notorious for their poor condition.
The refugees from the previous camp on Samos are to be relocated to the new facility on Monday.
According to the Greek Ministry of Immigration, the old camp will be closed at the end of the month.
In Greece, a particularly large number of refugees arrive on their way to the EU.
In 2015, more than a million people asked for asylum there.
In view of the Afghanistan crisis, the number of refugees is expected to rise.