People attend a real estate trade show held in Haikou, Hainan province. [Photo by Shi Yan/provided to China Daily]

Lao Li is typical of this group: retirees with houses of their own who spend about six months a year on the island.

There are about 400,000 of these "migratory birds", who live life at a leisurely pace in cities along the island's east and south coasts, socializing and enjoying the sunshine and sea views from the many beaches.

Sanya, population 740,000, is the most popular tourist city in China, according to official statistics, followed by Weihai in Shandong province, Hangzhou in Zhejiang province and Xiamen in Fujian province.

About 80 percent of the city's apartments have been purchased by mainlanders and it is common to spot vehicles with number plates registered to cities and provinces that are thousands of kilometers away, such as Beijing, Heilongjiang, Liaoning, Xinjiang, Shanxi, Shandong and Chongqing.

The percentage of homes owned by mainlanders is generally higher in other, smaller cities around the island, which has a total population of 9 million.

A series of events were held in Haikou earlier this month to mark the 980th birthday of Su Shi (1037-1101), an official and literary giant of the Northern Song Dynasty (960-1127), who was banished to the island for many years.

The activities served as a reminder that Hainan was once thought of as a wild and unforgiving place.

It no longer has that reputation, however, and in 2009 it was designated an international tourist island by the State Council.

Infrastructure construction has been fast-tracked and 51 international flights now link Hainan with major cities in 20 countries and regions.

In late 2015, the world's first high-speed railway circling an island started operations and an expressway network has also been built.

"Apart from the natural gifts such as the rainforests and volcanoes, the tropical island province has a lot more to offer: its unique history, rich ancient culture and delicious food－a top concern when traveling," said Wang Hua, a tourism researcher from nearby Guangdong province.

"Truly, Hainan is a paradise for food lovers－Wenchang chicken, Jiaji duck, Hele crab and Dongshan lamb, its various noodles, its 'Old Daddy's Tea'－just to name a few."

Zhan Lanlan, a mainland saleswoman who was traveling on the island, described it as a "romantic place to visit and a peaceful and leisurely place to stay".

Last year, about 60 million tourists visited Hainan and annual arrivals are expected to reach 80 million by 2020, according to a national strategy outlined in 2010.