The Bristol International Balloon Fiesta is held during August in Bristol, United Kingdom. Teams from all over the UK and other parts of the world bring their hot air balloons to the site and participate in mass ascents where as many as 100 balloons may launch at a time.
"The event is one of the largest in Europe and it is common to have crowds of over 100,000 on each of the four days of the festival. It takes place in a large country estate Ashton Court. Balloon launches are attempted twice a day, at 6am and 6pm, subject to weather conditions."
Click here to read the article I wrote about this year's fiesta for NowPublic.com.