GRES-2 Power Station at Ekibastusz, Kazachstan, has the world's tallest chimney. It was built in 1987 and is 419.7 metre tall.

At GRES-2 Power Station also the largest powerline in the world, the 1150kV powerline to Kokshetau starts ( http://en.wikipedia.org/wiki/Powerline_Ekibastuz-Kokshetau )

http://upload.wikimedia.org/wikipedia/de/2/23/Kraftwerk_Ekibastus.jpg
Power Station Ekibastusz. The left chimney is the tallest chimney in the world!

Further information
http://en.structurae.de/structures/data/index.cfm?ID=s0018365
http://en.wikipedia.org/wiki/Power_Station_Ekibastusz
http://en.wikipedia.org/wiki/Chimney_of_GRES-2_Power_Station

It doesn't look that tall.

Yeah unless that thing is way behind that smaller building and those power wires it sure doesn't look to big.

The height of the building of the power station may be 60 metres. When you compare this to the height of the chimney, than its height may be surely 419.7 metres. Interestingly the height of tall structures as chimneys, radio masts, TV towers is often estimated too small by most people.

Yeah the building is a bit far from the road I think. How tall is the other chimney?

that chimntey is ugly