Visitors to this years International Architecture Exhibition, the Biennale, in Venice are being asked to reflect on space and its implications. Whether this is space on water, space in buildings or simply space shared by human beings. Altogether 63 countries take part in the exhibition - six for the first time including Saudi Arabia, Guatemala and Lebanon. Many installations and projects have poetic meaning, but whether hidden or advertised, politics and current events are playing a big part in the pieces on show. The Israeli pavillion, for example, explores how different groups can share holy places. "We have to be aware of the political issues in order to make buildings which protect in so far as we can the status of the human being in the world," explains Shelley McNamara, co-curator of the exhibition, "that's a very general statement but architecture does have a political agenda which is maybe not specific to the political parties or whatever but it's a social agenda, it's a deep social agenda which has a deep political implication." The Vatican City is also making its Venice debut with 10 pop-up chapels built by architects from around the world.