Tap water in certain cities can cause stomach issues for tourists unfamiliar with local water standards.

Travelers often overlook differences in tap water quality, which can lead to digestive discomfort in various cities worldwide. Local water standards and treatment methods vary, sometimes exposing visitors to unfamiliar bacteria and contaminants. Understanding where tap water may not be safe and following precautions like using bottled or purified water helps avoid waterborne illnesses. This guide highlights cities where tourists should exercise caution and use safe drinking water practices.