The task of cleaning up Bangkok’s polluted canals

A huge network of canals (khlongs) criss-cross Bangkok and hundreds of thousands of people travel on them.

Over the years the canals have become badly polluted with rubbish from houses, stalls and restaurants which line the sides of them, but now work is under way to clean them up.

New boats are also being introduced and it is hoped more people will start using the canals and ease congestion on the city’s busy roads.

The BBC Travel Show’s Henry Golding reports.

First transmitted in April 2017.