As fear continues to spread that ISIS is on the doorstep of Europe—first after the Charlie Hebdo attacks in Paris, the Copenhagen shooting, and now the rapidly worsening situation in Libya—new examples of the jihadists moving in on us and among us are ever more worrying.

Last week, the international news network France 24 paid a visit to the tiny 17-square-kilometer Spanish enclave on the north coast of Africa, accessible across the Strait of Gibraltar, which is quickly becoming known as the “the jihadi capital of Europe.”

According to the report, the Principe neighborhood there is a den of iniquity, thick with drugs and arms dealers who “rub shoulders with more and more young people signing up to become jihadists.” The mostly Muslim population of Principe has become a recruitment pool for extremists from nearby Morocco who have infiltrated the mosques to find disgruntled, bored young men who are easily radicalized.

In January, police arrested two pairs of brothers who are suspected of planning an attack in Spain. Before their arrest, they are thought to have written a warning, “Charlie [Hebdo] was nothing, the Islamic state is just beginning.”

Most disturbing to the local community and Spaniards in general is that the young men who were arrested blended in, even defying some Muslim traditions in order to appear less radicalized, according to the Spanish Interior minister Jorge Fernández Díaz. “These were brothers who were highly radicalized, who worked in a military way, and were mentally very well trained,” Díaz told the press. “They were on the verge of carrying out an attack.”

Related: Italy Fears ISIS Invasion From Libya