(CNN) -- Urban cityscapes uniting large and vastly diverse populations have long been sources of great inspiration, commerce and community spirit, but for as long as they have existed, cities have also been beset by their own dangers.

While it's a fair to say no city, where humans interact freely, is spared the scourges of violence and criminal activity, it is also evident that some are far more affected than others.

It's a tall order to quantify these problems and rank cities in terms of the most dangerous, particularly in countries so ravaged by conflict and chaos that day-to-day safety is only a distant dream for many inhabitants.

Such concepts of danger may also be highly subjective, with what is considered nothing more than a nuisance by one person being another's living nightmare.

Nevertheless, studies have identified a handful of cities -- where comparable data is available -- considered more risky than others.

As part of our Urban Planet series, which also explores the most desirable, the most successful places to live as well as some of the pitfalls and positive aspects to city living, CNN looked at some of these population centers.

Cited from data collected by Mercer's latest global report on personal safety and Foreign Policy magazine's most recent report on murder rates, as well as reports by Forbes and security watchdog Citizen's Council for Public Security (CCSP), we have compiled a list of those considered among the most dangerous.

These surveys base their findings on factors such as internal stability and effectiveness of law enforcement, as well as official crime statistics and media reports.

Do these cities deserve their reputation? Comment below.