World Youth Day in Sydney in 2008 was incredible.
Nearly a million young people joined Pope Benedict down under for a week of prayer and reflection with some fun thrown in too.
Over 170 nations were represented and WYD08 events were watched live by an estimated international TV audience of 500 million, with TV and internet audiences combined reaching 1 billion.
In this series of short videos we've had put together you'll get a feel for this unique experience.
This video has been put together for us by Adam Brown of metafilms.co.uk.
For more from the Catholic Church in England and Wales visit catholicchurch.org.uk