Once the city of Bangkok was encircled of walls, 14 forts and 16 gates. As time progressed the walls did not last - leaving only parts of it still intact.
The area between the wall and the rivers became home to a number of people over six generations. There was talk of the area being turned into an 'eco-tourism' spot but this ran into a lot of opposition.
However the eviction and demolishing of homes has slowly been taking place with instructions of 'places not of historical interest'. Here is some information that has been collected - http://seajunction.org/gallery/glimpses-of-southeast-asia/people-mahakan-fort/.
I did not enter the the villages as it was not clear how to get there and I did not want to seem too nosey.