To visit Havana in the late spring, before the torpid humidity and showers of summer, is a glorious thing. Strolling through the streets of La Habana Vieja, its derelict and weather-worn facades still elegant, one encounters the grandeur of squares such as the Plaza de la Catedral, its church built in 1727, where leisurely cats and songbirds find refuge from the exhaust fumes that plague so much of the city.

As they have for decades, at dusk fishermen cast their lines and nets off the Malecón and into the splashing Caribbean, the sun descending as a fiery globe into the sea before them. In Vedado, once a glittering nightlife destination for the 1950s jet set, the old houses and green parks manage to catch some afternoon coolness as they slouch down towards the bay.

The last few years have one been ones of rapid change in Havana, one of the world's great iconic cities for well over a hundred years and a traditional weathervane of the fortunes of the country as a whole. The days where it served as a kind of an open-air museum where time stood still appear to be drawing to a close, with the opening of a long-closed system generating an inevitable tension and dynamism.