When you get into the rural parts of India, especially in North India, you will find such structures in a lot of places. These are brick kilns, where topsoil is mixed along with a few other materials, and then fired in these kilns at high heat to form the hard bricks. These bricks are then put in the sun to dry. This kind of work can be real hard, especially in summer, but they do provide work for people. As a byproduct, these kilns also cause a fair amount of pollution of the surrounding areas due to the fumes.