Spirit Houses on my walk along the local khlong

On my walk along the khlong near our home during Covid-19 I was amazed at how many Spirit Houses that I could see.

From Wikipedia, the free encyclopedia. 

A spirit house is a shrine to the protective spirit of a place that is found in the Southeast Asian countries of Burma, Cambodia, Laos, Thailand, Malaysia, Indonesia, Vietnam and the Philippines. The spirit house is normally in the form of small roofed structure, and is mounted on a pillar or on a dais. They can range in size from small platforms to houses large enough for people to enter. Spirit houses are intended to provide a shelter for spirits that could cause problems for the people if not appeased. The shrines often include images or carved statues of people and animals. Votive offerings are left at the house to propitiate the spirits. More elaborate installations include an altar for this purpose.

I was surprised that they were so many alongside the khlong and not outside a home.