The Aspendos Theater, built in the second century AD, is one of the best-preserved ancient Roman structures to the east of Turkey's Antalya. MAO NING/CHINA DAILY

Turkey's annual tourism revenue reached a record high in 2019, as the transcontinental country has become one of the world's most-popular destinations.

Industry insiders attribute the boom to diversification.

The country attracted a record 45 million inbound visitors last year, a year-on-year increase of over 14 percent, official data show. Tourism revenue also reached $34.5 billion, a 17 percent increase over 2018.

Istanbul, which straddles Europe and Asia, received the most arrivals, at 15 million, accounting for a third of inbound visits last year. The Mediterranean resort city of Antalya, known as "the Turkish Riviera" for its beaches and historical sites, followed with 14.6 million inbound arrivals.

Turkey has become the sixth most-visited country, the United Nations World Tourism Organization reported recently.