The global architectural  extravaganza that is the World Expo is once again upon us and it is Milan's turn to play host.

The original master-planners, a team that included Swiss architects Jacques Herzog and Pierre de Meuron, walked out in 2011 after their vision for a new typology of the Expo, one based on content rather than the individualist (and often propagandist) architecture of national pavilions, was rejected by the organisers.

The results - despite much decried construction delays and other colourful scandals - were in turn demented, elegant, garish and at times audacious; a sort of global Eurovision song contest in building form. Often the exhibition's avowed theme, Feeding the Planet - Energy for Life, seemed merely an excuse to have a restaurant outlet and/or a shop selling national produce.

Standout designs were few and far between, though the pavilions of Bahrain and UK alone did much to restore the faith. The former was a rich collection of fragrant walled fruit gardens intersected by roofed exhibition areas that provided moments of mystery, surprise and release. Entirely made out of 350 curved and straight prefabricated concrete panels, it will be disassembled and shipped to Bahrain for a second life as a botanical garden.

The latter tackled the exhibition's theme head-on by creating a small oasis that celebrated the very necessary toils and endeavours of bees in global food production. The climax was a metaphorical hive made out of 169,000 aluminium components and LED light fittings that sparkled and pulsated according to the activity of a real hive in Nottingham.

In some cases the architecture was not aesthetically pleasing but the concept was strong. Switzerland's pavilion resembled a supermarket depot, with four towers filled with products abundant in the country - coffee, water, apples and salt (who knew?). Visitors were allowed to take as much of each item as they wanted. 'When the food runs out, it runs out,' said a young woman dramatically as people walked in. 'The life of these towers is in your hands.' The structure is designed to come down floor-by-floor as the food is consumed. The underlying idea was neat and thought-provoking: if we all consume in moderation there's enough for everybody. If we don't, well… you get the picture.