Saigon Palace, the world-famous tourist destination in Vietnam, is ranked the most visited city in the world.

But while Singapore has a strong reputation as a modern and stylish capital, it is also one of the world top five most polluted cities in the World.

Here’s how to spot the smoggy spots.1.

The Red River2.

The Saigon Tunnel3.

The Blue River4.

The Yellow River5.

The Green River6.

The Tanjong Pagar7.

The Ho Chi Minh Trail8.

The Chao Phraya River9.

The Champs-Élysées10.

The Bien Hoa River11.

The Yangon River12.

The MRT16.

The Dong Khut River17.

The Mekong River18.

The Suez Canal19.

The Great Wall20.

The South China Sea21.

The Spratly Islands22.

The Pacific Ocean23.

The Bay of Bengal24.

The Arabian Sea25.

The Caribbean SeaThe ranking is based on a study conducted by the World Health Organization (WHO).

The World Health Report is a compilation of WHO data on the health of the human population around the world, including diseases and deaths, and includes information on pollution.

It includes information about health, sanitation and environmental quality.

The report is available at: http://www.who.int/whs_publications/documents/health_report_2016.pdf The WHO report also notes that the pollution levels in some countries may be higher than those in others.