CLUNKY Trabants belching car exhaust along Karl-Marx-Allee. Red-and-yellow East German flags fluttering from storefronts. Retro-chic cafes that resemble cold-war bomb shelters. The Berlin Wall may have fallen 20 years ago, but in certain pockets of this pulsating German capital, it seems to be going back up — at least for those too young to recall what life was like in the German Democratic Republic. From stylish hotels that resemble 1970s Soviet housing to boutiques that elevate kitschy East German goods to high design, Berlin is still divided — on whether the Iron Curtain was cool. There's even a German word for it, “ostalgie,” a combination of the words “ost” (east) and “nostalgie” (nostalgia). Frozen in time Few vestiges remain of East Berlin. Bullet holes have been filled in, squatters evicted and weedy lots paved over for entertainment complexes. But spend enough time strolling the twisting backstreets and you might come across a building, a courtyard or a block that looks frozen in 1989. Most are on the city's fringes, but there's a stretch of Auguststrasse, the art mile in the Mitte district, in drab contrast to the slick galleries and Ikea-fied apartments. A former Jewish hospital at Nos. 14-16 is still gray as charcoal. A block away, at No. 5a, one side of a courtyard is pocked with bullet scars. Look now, before construction cranes encroach. TV dinner The Sputnik-inspired Television Tower was erected in the 1960s by East Germany to demonstrate its technical superiority. At 1,207 feet, it remains Berlin's tallest structure, as well as one of its most touristy. Skip the line by dining at its space-saucer-style restaurant, Telecafé (Panoramastrasse 1A at Alexanderplatz; 49-30-247-5750; www.tv-turm.de), which offers revolving views of the once-divided city. It's every bit as cheesy and memorable as it sounds. Party like it's 1989 For modern beats in a retro lounge, climb the rickety scaffolding to Klub der Republik, or K.D.R. (Pappelallee 81; www.myspace.com/klubderrepublik), a grungy hangout in Prenzlauer Berg named after the Palace of the Republic, the dismantled East German parliament building. Indeed, the globe lamps were salvaged from there. The music is played by a rotating cast of floppy-haired DJ's. Hello Lenin! Berlin has 170-plus museums, but only one examines how ordinary East Berliners lived under Communist rule — another example, perhaps, that reunification is a work in progress. The small, privately financed DDR Museum (Karl-Liebknecht-Strasse 1; 49-30-847-12-3731; www.ddr-museum.de) opened in 2006 and offers a playful trip behind the Iron Curtain with authentic artifacts and archival film. Those haunted by the 2006 Oscar-winning film “The Lives of Others” should also pay a visit to the Stasi Museum (Ruschestrasse 103; 49-30-553-6854; www.stasimuseum.de), housed in the former Stasi offices. Embassy Sweets If the weather is nice, head north to the leafy district of Pankow, where the East German elite lived. Along the way, stop by Stavanger Strasse, the old embassy row where the Cuban flag still flies, before heading to Majakowskiring, a road lined with stately villas including No. 29 — the former home of Wilhelm Pieck, the first president of East Germany. For hearty salads and sweet plum cakes, sit under the linden trees at Majakowski Gasthaus (No. 63; 49-30-4991-8250), an inn with a delightful garden cafe. End your visit at the Sch?nhausen Palace (Tschaikowskistrasse 1; www.spsg.de), a baroque castle that once served as the seat of the East German president; it is scheduled to reopen in December. Neue galleries Karl-Marx-Allee, the monumental but graying boulevard of Stalinist architecture, is welcoming a steady parade of art dealers. In the last year or so, galleries like Capitain Petzel (No. 45; 49-30-2408-8130; www.capitainpetzel.de) and Krome Gallery (No. 82; 49-30-280-946-59; www.krome-gallery.com) have planted their flags along the concourse, giving other new art districts in Berlin a run for their money. Private collectors are also taking over palatial spaces, including Sammlung Haubrok (Strausberger Platz 19; 49-30-8061-9287; www.sammlung-haubrok.de), which showcases contemporary artists like Jonathan Monk and Martin Boyce. Cuddly cars Berlin was a huge city even when it was divided. To cover more ground, see old East Berlin behind the wheel of a Trabant, the plastic car that was a symbol, for better or worse, of the Communist regime. Trabi-Safari (49-30-2759-2273; www.trabi-safari.de) has a cuddly fleet that chortles past landmarks like the East Side Gallery in Friedrichshain (www.eastsidegallery.com), at the longest existing piece of the Wall, which is being unveiled next month after a controversial mural restoration. Tours start at 30 euros. People-owned goods Plastic blue egg cups. Interflug luggage tags. Vintage drink carts. For groovy East German goods at moderate prices, bring your tote bag to Arkonaplatz, a little park at the edge of Mitte that becomes a retro-trendy flea market on Sundays (www.troedelmarkt-arkonaplatz.de). Cute cafes ring the park. Still looking for those big sunglasses? Walk along Bernauer Strasse to the sprawling flea market at Mauerpark, or Wall Park (www.mauerparkmarkt.de). While the quality has gone down, there are still some treasures among the pirated DVDs. The basics After a drought, a wave of hotels is opening on both sides of where the Berlin Wall once stood. To the east is the Ostel (Wriezener Karree 5; 49-30-2576-8660; www.ostel.eu), a “communist retro” hostel with East German interiors, not far from the Ostbahnhof. Doubles with private bathrooms start at 61 euros ($91.50 at $1.50 to the euro); bunk beds start at 9 euros. A worthy rival in the former East Berlin is the Arcotel John F. (Werderscher Markt 11; 49-30-405-0460; www.arcotel.at), a cosmopolitan hotel with 190 rooms, starting at about 108 euros, based on a recent Web search. It's a good value because of its central location, well-designed furniture and attentive staff.