Close on its heels was Hanoi with the capital welcoming 1.5 million guests, while Sam Son Beach in Thanh Hoa Province was mobbed by 936,000 visitors across the month.
Since 2005, there has been an upward trend in Vietnam's tourism revenue. In 2015, Vietnam made $15 billion from tourism.
The number of travel agencies has increased over the years.
Vietnamese people seem to be favoring inland travel destinations with numbers steadily rising since 2011. However, the number of foreigner visitors touching down in Vietnam has fallen sharply.
In May, Khanh Hoa welcomed 1.6 million people, an increase of 14.37 percent from the same period last year. About 1.5 million people chose to visit the capital, up 10 percent, while Thanh Hoa welcomed approximately 20 percent more visitors.
Source: Institute for Tourism Development Research
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