Rheinturm

Finished in the year of our lord, 1981, the Rheinturm (Rhine Tower) in Düsseldorf is a monolithic communications tower built for both utility and recreation, and is even a clock for those who know how to read it. 

The nearly 600 foot needle sits right in the heart of the city, providing coverage for radio and television signals but is also open to the pubic with an observation desk and a classic revolving restaurant. As the tallest building in the city by a long shot, its bright neon lights can be seen all across the area during the evenings. 

Alongside these more mundane features, the concrete shaft of the tower also features a series of light spots that act as the world's largest digital clock. The trunk of the spire is intersected into three portions by two rings of red lights with the top third counting the hours, the mid-section counting the minutes, and the lowest level measuring the seconds. The various times are described not in numbers but by a series of dots, making the clock a sort of open secret. 

While the Rheinturm is not the tallest tower in Europe or even Germany, its massive clock makes it one of the more impressive of the show spires in the whole continent.