Trams have operated in Berlin since 1895, while the first double-deck buses first appeared on the city's streets in 1907. But a quarter of a century ago, Berlin was a divided city.
Following the Second World War, the conquering allied powers took control of Germany, dividing the country into four zones. Berlin lay in the Soviet zone but, as it was the capital city, it too was divided into four zones under military control. Relations between Soviets and the other allies deteriorated, ultimately resulting in the construction of the Berlin Wall which split the city in two. 9th November marks the anniversary of the fall of the Wall, in 1989.
While Berlin was split, its transport systems developed in very different ways.
West Berlin, by now a sealed-off enclave controlled by Western allies, abandoned its trams as it developed its bus and U-Bahn (metro) systems.
When I first visited Berlin in 1990, shortly after the Wall had fallen, buses in the West were a mix of single- and double-deckers.
The ruined church, in the centre of West Berlin, serves as a permanent reminder of World War 2. The church was destroyed in an air raid in 1943.
Although West Berlin had got rid of its trams, on the other side of the Berlin Wall the tram system had survived.
East Berlin's buses were very different to those on the western side of the Wall. Whereas West Berlin had kept double-deckers, articulated buses operated in the East.
These images (right and below) were taken on Friedrichstraße in 1990, looking north (right) and south (below).
For more images of transport in Berlin during the years that the city was divided, the Busworld Photography blog includes plenty of images taken during that era.
The images below were taken at the same spot as those above, in 2013. In the intervening 23 years, Friedrichstraße had changed almost beyond recognition.
Berlin's tram network continues to operate mainly in former East Berlin. Trams from the communist era are still plentiful. These high-floor trams do not provide step-free access.
The image below was taken in Alexanderplatz, which became the centre of East Berlin during the years that the city was divided. The World Time Clock, installed in 1969, is another relic of East Germany's communist regime.
It is unusual to find the communist era trams running as single units. During a visit to Berlin in 2008, however, I found this one. At the time, there was a shortage of serviceable trams due to an industrial dispute.
Although these trams have been extensively refurbished, their days are numbered as new trams are on order to replace them.
Berlin's TV tower is one of the city's iconic sights. Like the World Time Clock, it was built in the 1960s by the East German communist regime.
Many of Berlin's trams have doors on one side and a driving cab at one end only.
There are, however, some places on the network where the terminal is a dead end rather than a loop. The Alexanderplatz terminus of line M2 is an example.
On routes such as these, trams with driving cabs at both ends, and doors on both sides, are required.
Although much of the tram network is in the former East Berlin, since reunification a couple of links into the west have been restored. One example is along Bernauer Straße (below), running alongside one of the only sections of the Berlin Wall which still stands. Here, the wall section forms part of a memorial site to the division of Berlin, and to those people who lost their lives trying to escape to the West.
A further extension of the tram system into former West Berlin was being built at the time of my most recent visit in September 2013.
Once this section is open, trams will serve Berlin Hauptbahnhof, the city's new central railway station opened in 2006.
Of the places I have visited outside the UK and Ireland, Berlin is one of the few where I have found double-decker buses in use on the public transport system.
These long, three-axle vehicles have 83 seats, although only three tip-ups and a single fixed seat are step-free.
On the bus and tram network, routes prefixed with the letter "M" are "metro" services operating at high frequency throughout the day. They also run through the night although in some cases, not all of the route is served at night.
Although double-deckers are used on a number of routes, single-deck buses can also be found on Berlin's streets.
Some have two doors, others have three.
Three-door articulated buses also operate in Berlin.
At the time of writing, Berlin's main international airport is Tegel, to the north-west of the city, although this will in time be replaced by a new airport, Berlin Brandenburg International, to the south. Tegel isn't served directly by rail, but several bus services reach the airport.
Route TXL is a dedicated link between Tegel and central Berlin. TXL is the IATA code for Tegel airport.
Articulated buses are used on route TXL.
In some cities, special fares are charged on airport bus links. This is not the case in Berlin. Route TXL charges the same fares as any other service in Berlin.
Two other routes, 109 and X9, run to Tegel airport from Zoologischer Garten railway station. This image was taken nearby on Kurfürstendamm.
During the years that Berlin was divided, Zoologischer Garten was the main railway station in West Berlin.
Berlin's transport network is provided by Berliner Verkehrsbetriebe (BVG). The tariff system in based on three concentric zones. A single zone covers all of central and inner Berlin. A single fare is valid for 2 hours on bus, tram, U-Bahn and suburban rail services, with unlimited interchanges although round trip or return journeys are not permitted. Day tickets are also available, for individuals or small groups. The small group ticket, for up to 5 people travelling together, costs less than 3 individual day tickets.
A number of companies offer sightseeing tours of Berlin, using convertible open-top double-deck buses. Many of these vehicles doubtlessly started life on Berlin's streets as part of the city's regular bus fleet.
The water pipes in this image are a feature of Berlin. In this image, taken close to Friedrichstraße, the pipes are blue. Elsewhere, they may be pink, as shown in this BBC video report.
There are some newer vehicles on sightseeing work too.
A quirky reminder of East Germany survives on Berlin's streets.
Many of the city's pedestrian lights feature a rotund man wearing a hat. These symbols were introduced by East Germany. Following reunification, they began to disappear in favour of the slimmer pictograms used by western countries. This provoked a public outcry. As a result, the East German "ampelmännchen" not only survives in former East Berlin, but has also now spread into the west.
The cult status of the "ampelmännchen" is being exploited commercially. The "Ampelmann" shop (website in German), with several branches in central Berlin, has adopted the figure as a trademark.
Finally, as I mentioned earlier in this post, 9th November marks the anniversary of the fall of the Berlin Wall, an event which symbolised the end of the division of post-war Germany. But that is not the only anniversary which falls on this date. A terrible event occurred on the night of 9th November 1938. It was on this night 75 years ago that Jewish people were subjected to extreme violence in Berlin and in cities across Germany and Austria. Kristallnacht (the "night of broken glass") was pivotal in the lead up to the Second World War, and is often considered as marking the start of the Holocaust. The BBC website carries a video report of the events of that night.