WaterLinks through USAID facilitated a twinning partnership between Cambodia's Phnom Penh Municipality in and the Philippines' Iloilo City in 2008 on advocating better hygiene practices.  Both are members of the ASEAN Environmentally Sustainable Cities Initiative.  The partnership included developing and implementing a range of sanitation and hygiene promotion activities in Phnom Penh's Russei Keo district based on IloIlo's successful experiences in conducting hygiene promotion events. That knowledge, combined with an environmental health survey of the district, led Phnom Penh to become a testing ground for a WaterLinks toolkit on promoting and improving water, sanitation and hygiene programs. Building on the twinning experience and the toolkit, the Phnom Penh Municipality organized Cambodia’s first-ever water, sanitation, and hygiene (WASH) promotion day which drew over 1,200 participants.