Cambodia is expected to receive 3.3 million foreign tourists this year, a 15 percent rise year-on-year, Prime Minister Hun Sen said Thursday. "The country's cultural and eco-tourism has seen remarkable development, there is steady growth from year to year," he said in a message to mark the 33rd World Tourism Day. "This truly demonstrates that Cambodia has peace, political stability, security and safety, better infrastructures, clean resorts and good services." He said last year tourism industry attracted 2.88 million foreign visitors, earning 1.9 billion U.S. dollars, equivalent to 12 percent of the nation's GDP. Speaking at an event to celebrate the 33rd World Tourism Day on Thursday, Permanent Deputy Prime Minister Men Sam On said that tourism is the country's green gold. The country has two world heritage sites. One is Angkor Wat Temple in Siem Reap province, situated 315 kilometers northwest of Phnom Penh, the capital of Cambodia, and the other is Preah Vihear Temple in Preah Vihear province, located about 500 kilometers northwest of Phnom Penh. Tourism industry is one of the main four pillars supporting the economy. The others are garment industry, agriculture and real estates.