This is a brick manufacturing kiln completed in 1890 designed by Hoffman, German engineer. This kiln is donut shaped. Bricks made here were used to build modern buildings, gates, chimneys and railway bridges. 
The big donut space is divided in 16 chambers. Bricks are carried in from the small U shaped entrance.
Bricks are piled up like this. As fire travels around the circular kiln, each process of brick firing, cooling and taking out is made successively. One circle of firing takes 23 days. One hundred years ago, this kiln design was very efficient.
Every chamber has 25 square holes on the ceiling from which coal powder is put in. Powder is delivered in containers on circular rails.
Outer wall has been exposed the weather. Thank you for the good work.
A pair of owl is growing their children in a hole of this big tree.