EXECUTIVE SUMMARY This report documents the use of immigration detention on the Eastern Aegean Island of Kos. Kos hosts one of five Greek EU hotspots and the only pre-removal detention centre (PRDC) on the Eastern Aegean islands. Since January 2020, the Greek authorities have detained nearly every asylum seeker who has arrived there, leaving many people to linger in detention for months, and often more than a year. Section I provides context for this report by detailing the history of immigration detention in Greece and Europe more broadly. This section shows that prior to the so-called migration crisis of 2015/2016, immigration detention was on the decline in Europe, in response to growing public concern about human rights abuses in detention. However, the tide shifted in 2015 and 2016 as nearly one million asylum seekers arrived at Europe’s border and states sought to keep people from entering Europe. That history sets the stage for the practices on Kos today. Section II introduces the situation on Kos and outlines the report’s scope. Section II explains that the report has two separate scopes. First the report explores the legal grounds for detaining migrants in Greece and what procedural guarantees the authorities must provide to them. Second, the report looks at the living conditions in the Kos PRDC and highlights the physical and mental toll detention can take on refugees and asylum seekers. Section III introduces the first scope of the report: the legal grounds for detaining migrants in Greece and the EU and juxtaposes them against the practices on Kos. Section III distinguishes between asylum seekers – people who are in the asylum procedure – and rejected asylum seekers who have had their applications rejected at the second instance. Section III explains that under both Greek and EU law, the authorities can only detain asylum seekers exceptionally, and as long as there is no alternative, less coercive measure. However, as this section shows, the authorities on Kos have automatically detained all asylum seekers upon arrival, regardless of their individual circumstances or available space in the nearby Reception and Identification Centre. Section III also details the grounds for detaining rejected asylum seekers, showing that under Greek, EU, and human rights law Greece may only detain rejected asylum seekers for the purpose of their removal. However, the authorities on Kos continue to automatically detain rejected asylum seekers, even though returns to Turkey have been suspended since March 2020 and there is thus no prospect of return. Section III then goes on to lay out the legal grounds for detaining vulnerable persons before concluding that, in many cases, vulnerable persons are detained unlawfully on Kos. Section III raises particular concern about the authorities’ former practice of detaining families with young children and the ongoing practices with respect to survivors of torture and gender-based violence. Finally, Section III concludes by describing the procedural guarantees for detained migrants and the right to an effective remedy. Specifically, this part of Section III looks at detained persons’ access to the asylum procedure, legal services, and information on detention. We conclude that people have limited access to information about the asylum procedure, legal services, and information about the reasons for their detention. Section III also concludes that the right to an effectively remedy is severely curbed for people detained in the Kos PRDC. Section IV introduces the second scope of the report: documenting the living conditions for people detained in the Kos PRDC and Greece’s obligations to protect migrants’ human rights. The analysis in this section is drawn primarily from in-depth interviews with people who were detained in the Kos PRDC. Section A provides a general overview of the detention facility on Kos. Section B lays out the legal standards II DETENTION OF MIGRANTS ON THE ISLAND OF KOS