Spend a full free day exploring Phnom Penh however you like. Maybe visit the Royal Palace and Silver Pagoda. Wat Phnom, shrouded in myth, is equally worth a visit, as is the National Museum with its extensive Khmer collection. Cyclo tours around the city are a great alternative to exploring by foot. These tours generally include the art deco Psar Thmei (Central Market), US Embassy, Wat Phnom, Mekong riverfront, Independence Monument and Royal Palace. Or, you could learn more about Cambodia's tragic history at the Tuol Sleng Genocide Museum (S-21) and the Killing Fields of Choeung Ek – two sites that tell the story of the tragic legacy of the Khmer Rouge.