Buildings, in Berlin, tend not to be just buildings. They are manifestos, propaganda, memorials, battlefields. It is the city whose Wall was one of the most political works of architecture of all time. The confrontation of superpowers was condensed into Berlin's urban form, and the apartment blocks in the old eastern and western halves are imprinted with competing ideologies. Nazism, Communism, social democracy and capitalism have all felt the need to say it with buildings.

The biggest names of modern architecture also left their mark: Mies van der Rohe, Le Corbusier, Walter Gropius, Alvar Aalto. In the 1920s new ideas in architecture fomented there and, since the fall of the Wall, contemporary stars such as Frank Gehry, Rem Koolhaas, Norman Foster and Richard Rogers have been invited in. A good place to start a tour of highlights is the Kulturforum, where large sums were invested in cultural monuments by West Germany's government in order to boost West Berlin and to demonstrate its superior commitment to the highest works of civilisation.

The most spectacular of these monuments is the Philharmonie of 1963 (number 1 on the interactive map of the walk – click here to view), designed by Hans Scharoun and the home of the Berlin Philharmonic Orchestra. Its swooping, freeform design and gold-coloured cladding anticipate by some decades the "iconic" architecture of the 1990s and 2000s. Unlike some of the latter it is bold but not bombastic – there is a lightness and sensitivity about it, with an awareness of the flows of people which makes it a delight to walk through. Above all, there is the 2,440-seat auditorium, with irregular terraces of seating which Scharoun described as "vineyards".

Nearby is a library (number 2), also by Scharoun, and a striking science centre in pink and blue stripes by James Stirling. There is also the New National Gallery (number 3) of 1968, which is the polar opposite of the concert hall. It is solemn, temple-like, black, symmetrical, perfect, elegant, chilly. It is a late work of van der Rohe and one of his most extreme. Most of the art is buried in its stone plinth rather than the steel-and-glass superstructure, and van der Rohe confessed he'd have liked it if it had contained no art whatsoever, apart from a single Brancusi bird in its dead centre.

From the Kulturforum you can walk to Potsdamer Platz, once the centre of the city, then made into a wasteland by the war and the Wall, now filled in with a large commercial development which, despite the efforts of architects such as Renzo Piano, is somewhat soulless. A longish walk then gets you to Daniel Libeskind's Jewish Museum (number 4), a frenetic work of jagged angles and oblique lines which attempts to represent the extent to which the history of Berlin's Jews was enmeshed in that of the city itself, as well as the violence with which its two halves were torn apart.

Back in the vicinity of Potsdamer Platz, and also on the faultline where the Wall stood, is another work of expiation. This is Peter Eisenman's Holocaust Memorial (number 5) – a field of large concrete blocks with paths between them of rising and falling heights, such that sometimes you can see the surrounding city, and sometimes your view is only of concrete. Its devices of muteness and disorientation are almost commonplace in contemporary memorial design, but it is powerful for all that.

Pariser Platz is the starting point of Unter den Linden and has the Brandenburg Gate as its centrepiece. The square has been recreated as an approximation of what stood there before the war. It contains Frank Gehry's DZ Bank building (number 6) which, due to planning policies intended to promote an orderly city fabric, has one of his least exuberant exteriors. Inside it is a different matter, with an auditorium in the shiny, curvaceous, convulsive style for which he is famous.

You will by now have seen the glass dome that Norman Foster put on top of the Reichstag (number 7), a mountainous 1894 building which was notoriously burned in 1933, and whose capture in 1945 signified the final victory of the Red Army. Originally created for the somewhat limited democracy allowed under the Kaisers, it is now the home of Germany's parliament. Foster's design is about contrasting craggy old stone with a pristine glass architecture of democratic transparency. The public is allowed to roam a spiral ramp inside the dome, taking in wide views of the city, and look down on the debating chamber below as a sign of its superiority over its rulers.

Lunch by now is long overdue, and you should head past the grandiose headquarters of Angela Merkel to the Restaurant Paris-Moskau, north of the Tiergarten. This is in a quaint-looking inn which survived the war, whereas almost everything around it did not, and it offers food with Germanic tendencies – it favours, for example, things found in forests or dug up from the ground, such as chestnuts, cranberries and beetroot, but rendered in a sharp, avant-garde way. It is worth lingering over, so if you don't want your lunch leisurely you would be better off coming here for dinner.

Should you have the stamina (and in truth I'd recommend leaving this for another day) you can head back to Pariser Platz and on to the Neues Museum (number 8), where the British architect David Chipperfield has returned what was a bombed-out wreck to its original purpose as the home of a mighty archaeological collection. Chipperfield's work is a meditation on damage, with fragments of fresco and carving exposed alongside rough brickwork and clean new construction. He has been accused of fetishising destruction, but the main effect is for the history of the building to be showcased alongside the exhibits.

Here you are in the midst of several mighty museums built in the 19th century. You are in the old East, and as you progress you see the plattenbau, the severe factory-made blocks that the Communist regime favoured. You will see its virility symbol, the Berlin TV tower (number 9), and a large hole where its Palace of the Republic once stood. Nazi buildings in Berlin are preserved, in the name of remembering, but Communist monuments have been readily destroyed. It seems one form of tyranny can be forgotten, but not the other.

You could also head further east to the Dutch embassy (number 10), where Koolhaas tried to embody his country's reputation for being reasonable and open in a cubic building that allows views into its inner workings. You can visit it by appointment and experience an internal ceremonial route that ascends in a square spiral, catching views of Berlin's monuments as you go.

This is only scratching the surface. True devotees of modern architecture should travel to Potsdam to see the remarkable tower Erich Mendelsohn built for Albert Einstein, which succeeds at representing the physicist's ideas in masonry. There is also Bruno Taut's "horseshoe estate" in the suburb of Britz, a humane and beautiful garden city by an architect whose visionary pronouncements sometimes verged on the lunatic.

It should be said that Berlin's architecture tends towards the hard and harsh, and to attempt to see too many at once can be punishing. It's a good idea to leaven any tour with visits to the city's many cafés or the Tiergarten. The city has a nice line in independent shops, including the peaceful and relaxing Pro QM art bookshop. And the best way to finish is to go back to the Philharmonie and experience the purpose it was designed for – to hear exceptional music in an extraordinary space.