Adobe houses.
I guess you mean adobe; but most houses in Mexico are made of bricks.
Brick and cement blocks.
The Gulf of Mexico is a natural feature.
yes
Chinampas.
No. It is a natural gulf.
Natural
Two reasons: money and weather. See related questions for further detail.
10
Early men made houses out of animal skin, stone and bamboo sticks.
None. There is only the man-made border that separates the US from Mexico.
roro