The construction of Bati Atasehir (West Atasehir) started in 2006 and still goes on. The following links are showing the developments finished or in construction:
Atasehir Financial District, by RMJM
http://www.rmjm.com/projects/atasehir-turkey
Uphill Court
http://www.uphillcourt.com/atasehirt.htm
My World
http://www.myworld.com.tr/en/proje.asp
My Towerland
http://www.mytowerland.com/?from=agaoglu.com.tr
My Prestige
http://www.agaoglumyprestige.com/en/
Kent Plus Atashir
http://www.kentplus.com/atasehir/eng_default.asp
