Photo taken on Jan. 2, 2020 shows the sunrise scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 2, 2020 shows the sunrise scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 2, 2020 shows the sunrise scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 2, 2020 shows the sunrise scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 2, 2020 shows the sunrise scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 1, 2020 shows the sunset scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 1, 2020 shows the sunset scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 1, 2020 shows the sunset scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 1, 2020 shows the sunset scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)

Photo taken on Jan. 1, 2020 shows the sunset scenery of Luang Prabang on the riverside of Mekong River, Laos. Luang Prabang, located aside the Mekong River, was listed by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a world heritage in 1995. (Photo by Kaikeo Saiyasane/Xinhua)