In 1960, Rotterdam was the scene of the international horticultural exhibition Floriade. It was after Ahoy E'55 the third public exhibition in the adjacent Park. One of the major attractions of this first Floriade was an attraction tower 107 meters high, the Euromast. From the Euromast visitors had both a good view on the Floriade, the rebuilt city and the port. By the eccentric location near the port and busy roads, the Euromast is an iconic element in the city centre.
The building consists of a circular concrete mast or core of nine meters in diameter. Three hung pavilions: a circular entrance pavilion on the ground floor, a sort of ship's bridge at 30 meters altitude and an asymmetric top crow's nest are hung around it. The core was build in a speed of 15 to 20 centimeters per hour using a sliding formwork. In 23 days, they finished the core. Simultaneously, the components of the steel pavilions were constructed. The crow's nest was build at the foot of the mast and hoisted up in five days. The entire ship's bridge was constructed elsewhere. Finally, the circular base, finishing construction in a total of fourteen months. On March 25, 1960, the opening day of Floriade, the Euromast opened to the public.
In 1968, the Euromast lost its altitude record to the 114 meters high Medical School. For C'70, the last major exhibition in Rotterdam, the Euromast therefore was extended with a Space Tower. The Space Tower was made by a Swiss company Bühler AG Willy. It consists of a steel mast with a diameter of 2.50 meters, around which a circular booth circles.
Normally such masts are placed on the ground floor. Research showed that the Euromast was strong enough to bear this additional structure. It was also possible to anchor the mast properly. For the construction of the Space Tower a 140 meters high crane was used. The components of the Space Tower were placed in nine days. On June 5, 1970 the Euromast reopened for visitors and was with its 176 meters high, again the tallest building in Rotterdam.