In 1958 a 280 metres tall radio mast of the "Europe 1" transmitter in Felsberg-Berus had to be moved a way of 104 metres, otherwise the radiation pattern would have shown in the wrong direction. In order to perform this, the mast was lifted on a special railcar running on two tracks in paralell. On these tracks the mast was slowly moved, whereby the guys had to be adjusted permanently.
The following pictures show the used equipment
I believe, this was the tallest object ever moved on earth.