Complex sentence: The venue is the area surrounding the Kienberg that was originally known as "Berliner Gartenschau", a horticutural exposition held in 1987, in that times in East Germany, in commemoration of the 750th birthday of the city of Berlin.
Split into simpler sentences: The venue is the area surrounding the Kienberg that was originally known as "Berliner Gartenschau". This was the horticutural exposition held in 1987, in that times in East Germany, in commemoration of the 750th birthday of the city of Berlin.