Listed as #5 is St. Louis, the only U.S. city. 

"We have to make mention of one of the most divisive cities in the United States of America so we decided to list St. Louis. St. Louis and its surrounding areas were heavily in the news for the Ferguson riots but even before that the city had been heavily suffering from violence and disparate poverty. Despite successful sports franchises and a nice midwestern seat, St. Louis is an easy enough destination to avoid traveling to."

Some other cities listed were Rio DeJaniero; Cape Town, South Africa; San Salvadore; Nairobi; Acapulco; Barquisimeto, Venezuela; Sana’a, Yemen.