When I returned to Sofia as American ambassador in 2005 after a 20-year absence, I wasn't sure how much change I would see. My wife Jocelyn and I had got to know the city fairly well during our assignment to the embassy in 1985-87, and although we had followed the political transformations from abroad during the intervening years, I had no idea how much remained of the Sofia that my memory had somewhat romanticised.

Were the unique yellow bricks now covered with asphalt? Was there finally an underground metro? Had Western fast-food chains displaced the smoky, seedy cafés I used to patronise? What had become of that grandiose heroproject, the NDK? The two years since our return have afforded us ample opportunity to reacquaint ourselves with the remarkably adaptive city that manages to celebrate its heritage as one of the oldest settlements in Europe while struggling to meet the challenges of growth, development and change familiar to all European capitals.

Some of these challenges I've simply resigned myself to: the unpredictable quality of road and pavement surfaces, or the frustrations of traffic and parking. Other changes, however welcome they might be, still seem to resist growing familiar. I never pass through Battenberg Square, for instance, without sensing the absence of the massive hulk of the Georgi Dimitrov Mausoleum that dominated what used to be called 9th of September Square.

Like everyone who calls Sofia home – even if only temporarily – I have my catalogue of favourite sites and haunts. Many are themselves the emblems of Sofia and Bulgaria: the incomparable Boyana Church frescoes, the towering spire of the Aleksandr Nevskiy Cathedral, the public baths (especially when the restoration is finally complete), a mixed grill at Pod Lipite. But others are more personal, tied to memories of our earlier stay here, or linked to styles of art or aspects of life that simply appeal to me. The following is my somewhat random, idiosyncratic list:

THE RED HOUSE CENTRE FOR CULTURE AND DEBATE

This is for me the epitome of successful mixed-use architecture: a relaxed home with a touch of country spirit; a centre of Bulgarian intellectual and artistic life; an unpretentious place for food – and food for thought. Jocelyn and I have attended a number of debates and discussions, film showings or exhibitions at the Red House over the past two years, sometimes hugging the back wall of the large hall in a usually successful effort to remain incognito. Discovering that the derelict structure I recalled from the mid-1980s had been rescued and rehabilitated became for me something of a metaphor for the redemption of Bulgarian civil society as a whole.

*John Beyrle is the American ambassador to Bulgaria