The tower, finished in 1969 and 368 metres high, is the tallest structure in Germany and can be seen from nearly everywhere in the city. It was built by the East German government as a showpiece of socialist engineering, and when the sun hits its steel sphere, it throws a cross of light that Berliners cheekily called the Pope's revenge.
The neighbourhood is a mix of the grand and the plain, and it tells the whole story of the city. Nearby is the Nikolaiviertel, a reconstructed medieval quarter on the site where Berlin began, and the huge brick Marienkirche, one of the oldest churches in the city. A few minutes away is Museum Island, whose five museums on an island in the Spree were listed by UNESCO in 1999. Across the river the great boulevards lead to the Brandenburg Gate, and along the way you pass the remains of the Wall, a strip of cobbles in the road marking where it ran.
As a place to start a ride, Berlin is demanding. The streets are wide but busy, with trams whose rails can catch a thin tyre in the wet, cobbles in the older quarters, and a great many cyclists, scooters and delivery vans. Traffic lights are everywhere. Early on a Sunday morning the centre is almost empty and a pleasure, but at rush hour it is slow and stressful. Once you are beyond the ring road the landscape opens into forests and lakes, and the riding gets better quickly.
Fuel in the centre is limited, because the stations are mostly on the outer roads, so fill up on the way in or on the way out. Parking a bike in Mitte is easy to do and hard to do well, and a locked chain through the frame is sensible. Berlin eats late and stays up later, so there is no need to hurry.