In Berlin, the Ökohaus project remains something of an open secret. Completed in 1992, on land where the Vatican embassy once stood, the dwellings yield for much of the year to ruffled vines, vanishing completely from the casual onlooker — an almost absurdly lush, jungly break in the austere, ambassadorial streetscape. Their undoneness struck me as too deliberate to be a squat — the inhabited derelict buildings that were once a familiar sight in Berlin1 — but the varied exteriors were messy enough to suggest some kind of cooperative, countercultural living exercise. Through the overgrowth, one can see a hodgepodge of decontextualized styles and references — Cape Cod-style facades here, 1980s po-mo there; a lot of glass and wood and concrete, including futuristic-looking, glassed-in staircases snaking through the foliage; grass-covered roofs and concrete decks with metal fences trailing plants faintly reminiscent of Japan’s traditional hanging gardens. I could imagine Hansel or Gretel emerging from the green to open the gate. It was one of Berlin’s last remaining mysteries in a vast city that by then felt thoroughly discovered.

....

• 1. It has always been the Modernist buildings in the city’s former West that have fascinated and even moved me, from Le Corbusier’s Unité d’Habitation (an apartment building now known as Corbusierhaus) to the residential complex of Hansaviertel, just north of the park, which includes apartment towers designed by Walter Gropius, Alvar Aalto, Oscar Niemeyer and others. Both were the result of the International Building Exhibition’s Interbau 57, for which prominent architects of the era were invited to design residential housing in Berlin, just over a decade after the end of World War II. This, of course, was long before the money and glamour arrived, in those years of eerie stasis when West Berlin was a small enclave marooned within East Germany; the resulting buildings — inexpensive, socially attuned, beautifully rendered — were created in a burst of postwar idealism, helping to fill in the vast gaps in the cityscape and to house displaced people. Designed in keeping with the very principles Hitler had rejected, many of them by the visionary thinkers who fled the Nazis in the 1930s — including the former Bauhaus directors Gropius and Ludwig Mies van der Rohe — they communicate something powerful about the city’s vicissitudes, the troubling capriciousness of history.