Euromast is an observation tower in Rotterdam, Netherlands, designed by Hugh Maaskant constructed between 1958 and 1960. It was specially built for the 1960 Floriade, and is a listed monument since 2010. The tower is a concrete structure with an internal diameter of 9 m and a wall thickness of 30 cm. For stability it is built on a concrete block of 1,900,000 kg so that the centre of gravity is below ground. It has a "crow's nest" observation platform 96 m above ground and a restaurant.