Gulag DNC

The discovery of a makeshift jail in Denver's warehouse district is causing outrage among some protesters.

The jail was apparently constructed to house protesters during the Democratic National Convention but the city never publicly announced plans to construct this kind of facility.

Members of the group Recreate '68 are calling the detention center "Denver's inhumane and dirty little secret," "Guantanamo Bay on the Platte" or "Gitmo on the Platte." The warehouse is just feet from the South Platte River.

The jail is made up of large fenced-in cages with razor wire on top. The city said those cages are for the safety of law enforcement agents and those who are arrested. Activists call it a concentration camp unfit and inappropriate for human detainees.