San Francisco is one of the most exciting, dynamic, and richest cities in the world.

But it's far from being the cleanest.

In February, the NBC Bay Area Investigative Unit spent three days surveying 153 blocks of downtown San Francisco to see what they would find. Their search turned up drug needles, garbage, and feces in concentrations comparable to some of the world's poorest slums.

On a recent commute to Business Insider's office in San Francisco, I took a detour through the Tenderloin neighborhood, where NBC conducted its survey, to see how the claim held up.