The official meetings and side events of the UN Conference on Sustainable Development, Rio+20, were held at Riocentro: a massive and very pedestrian un-friendly venue located 14 miles (in a straight line, following the coastline it would be about 20 miles) from the city of Rio de Janeiro.
Try to imagine having an event in New York in which the conference venue is at Rockaway beach, then subtract the subway and double the number of cars in the street. Point being: commuting was nightmarish. This was, of course, for a reason: it was the only place to accommodate such a large number of people.
In my initial accounts, I thought this was a good metaphor about the scope of the event and how trying to cover so much usually leads to little results.
Read more: First Impressions at Rio+20: A Question of Scale?