Here we are at the Theater des Westerns. Josephine Baker appeared here; so did Enrico Caruso and Marlene Dietrich. It's still an active performance venue. But the hulk itself? It was built in 1895-96 to a design by Bernhard Sehring in a style described as Wilhelmine historicism. Watch as solid walls such as these gradually vanish from the buildings erected in Berlin over the following century.

Not a lot more glass here. It's the limestone office wing at Templehof Airport. (Only the head of the iron eagle survives, the rest having been removed in 1962.)

Until then, the eagle rested atop the building, designed by Ernst Sagabiel as part of Albert Speer's plan for Berlin. There's nobody in the picture because Templehof closed in 2008.

A plaque recalls the airlift.

The airport concourse radiated from both sides of that entrance hall to form a quarter-circle over a kilometer in length. The other side of the structure was a huge roof, so aircraft could park under cover. Call it a precursor of the jetbridge. The airport was supposed to be Lufthansa's headquarters, but after the war, it instead became the terminus of the Berlin airlift. PanAm flew here from 1950 to 1975. The U.S. military used it until 1981.

More glass still. This is now called the Pallaseeum, from the Pallasstrasse it straddles, but was originally the Sozialpalast, a palace for the common man. By whatever name, it contains over 500 apartments and has come back from a nadir in the 1990s, when it was almost demolished. Designed by Jurgen Sawade, the building was begun in 1977 on the site of the Berlin sports palace, built in 1910 for winter sports but often used in later years for political rallies.

More, more, more. Alliance Real Estate is one of the largest landlords of office and retail space in Europe and appropriately enough is housed in Germany's tallest office building, which is part of Treptowers, built in 1998 on the site of the 1926 workshops of AEG, or German General Electric. The concrete in the foreground is the bed of the Spree River.

This is Ludwig Erhard Haus, completed in 1998 and designed by Nicholas Grimshaw. It's the home of the Industrie-und Handels Kammer, or Chamber of Commerce and Industry. It also houses the Berlin Stock Exchange. The structure consists of 15 immense arches, and its exterior would have followed their curves if the local government had not insisted on conventional, vertical walls.

Not quite vertical: one of the eight buildings of the Jakob-Kaiser-Haus, which opened in 2002 and houses offices for over members of the German parliament.