A dark, despairing nation whose weary inhabitants cowered beneath the worn-out regime that ruled them so ineptly. So much for Thatcher's Britain in 1989; in East Germany life was even worse.

The Second World War might have ended more than four decades earlier, but 20 years ago Germany was still an occupied nation. The way that the country's carcass was carved up by Britain, France, the US and the USSR had all kinds of odd consequences for the traveller. One was that no West German airline could fly domestically from Hamburg, Frankfurt or Stuttgart to Berlin. The national carrier, Lufthansa, was banned from the country's main air routes, leaving the market to British Airways, Air France and Pan Am - all of whom prospered out of this constraint on trade. Fortunately for the budget traveller, fares to Berlin from Munich, Frankfurt and Hamburg were subsidised by the German state. So one bleak morning in January 1989, I strode up to the Pan Am counter at Frankfurt airport and handed over the equivalent of £75 for ticket to Berlin (and back, since I was feeling lucky). The new anxieties about terrorism in the wake of Lockerbie - Pan Am 103 had been bombed a few weeks earlier - were displayed when a couple of fellow passengers of Middle Eastern appearance were detained for further questioning.

The trajectory of the short flight to Berlin was unusual. The pilot flew at normal altitude initially, but had descended to 10,000 feet by the time we reached the West-East German frontier. The rules on access to West Berlin from the rest of West Germany insisted that aircraft stick to specified air lanes and altitudes - and, since the rules had been drawn up before any high-altitude passenger jets had been invented, the maximum height was decreed in the era of propeller planes.

The Boeing 727 landed in West Berlin, and I caught a transfer bus and then the U-Bahn (underground railway) to East Berlin. It really was as simple as that: line 6 of the U-Bahn ran directly beneath East Berlin. All the stops in the eastern part of the city were bricked in and heavily guarded "ghost stations", except one: Friedrichstrasse. Today, this junction between underground and overground looks like any other busy city-centre railway station. But 20 years ago it was one of very few places where the axis of liberal democracy intersected with the axis of the Bolshevik Revolution.

Curious tourists were seen by the German "Democratic" Republic as a source of much-needed hard currency. A day visa cost 25 Deutschmarks (about £10). In an attempt by the East German authorities to stifle the rampant black market, the East German authorities insisted on the mandatory exchange rate of 25 (valuable) DM for the same number of their (near worthless) Reichsmarks.

Like Cinderella, the day-tripper had to be home by midnight. But a short appointment at a shabby office on Alexanderplatz, plus another wad of hard currency, was enough to secure permission to stay longer.

Two days in East Berlin passed in an instant - discovering a city that was so beautiful, so cultured, yet so alien, and meeting locals who were trapped in an ideological deep-freeze. They were guarded (in at least two senses), fearful of straying across the ill-defined line between international comradeship and potential espionage. Neither they nor I fancied a speaking part in the real-life Cold War drama set on the city's austere streets. When we said farewell, it might as well have been forever: no one could believe the Wall would melt away in our lifetimes.

I returned through Checkpoint Charlie at dawn. The colour of your passport decided whether or not you could escape from a land ruled by fear, in the shape of the Stasi (state security organisation), to the free world. That dark, icy January morning in 1989, the main exit from the Eastern bloc was softened by mist. My heart raced as I passed through the stern barriers and sterner guards who protected the "death-strip" that separated communism from capitalism. Within a year, the Berlin Wall had gone and the city had come back to life. Yet, as I discovered last weekend (see pages 10-11), the long division adds a fascinating dimension to the German capital. The faceless bureaucrats and black marketeers have turned into stalwarts of the business community, some of them selling chips of the Wall for €12.90; but enough of the barrier remains to take you through the past, darkly.