Construction: between 1958 and 1960 Architect: Hugh Maaskant. Material: concrete building Dimensions: internal diameter of 9 meters (30 feet) and a wall thickness of 30 centimetres (1 feet). To keep this tower stable a concrete block of 1,900,000 kilograms (4,190,000 lb) was poured below ground level so that the center of gravity is located there. There is a "crow's nest" observation platform 96 meters (315 feet) above-ground and also a restaurant.
Construction: between 1958 and 1960 Architect: Hugh Maaskant. Material: concrete building Dimensions: internal diameter of 9 meters (30 feet) and a wall thickness of 30 centimetres (1 feet). To keep this tower stable a concrete block of 1,900,000 kilograms (4,190,000 lb) was poured below ground level so that the center of gravity is located there. There is a "crow's nest" observation platform 96 meters (315 feet) above-ground and also a restaurant.