Dutch travellers visiting U.S. less often; Asian cities becoming more popular - Southeast Asian cities rank among world's most polluted - An Asian city is named the safest destination in the world for travelers - This Southeast Asian city is the world's most expensive for the super rich -- Hong Kong comes second - 'Mumbai has become the Asian city with the most billionaires, beating Beijing' - Asian cities gain ground in Euromonitor's 'Top 100' cities to visit