Oxfam TRAILWALKER, Oxfam Australia's biggest fundraiser, is a unique endurance challenge in which teams of four traverse a 100klm bush trail in under 48 hours. This year's Oxfam TRAILWALKER Sydney event sees the highly anticipated unveiling of a new trail - from 'the Harbour to the Hawkesbury'. Starting at Chowder Bay in Mosman, the teams will tackle the beautiful and at times rough terrain that northern Sydney has to offer, as they wind their way northward through the bush corridors of some of Sydney's most stunning National Parks to complete the 100 kilometres at Brooklyn. Can you step up to the challenge?