Honored were the 11th century Preah Vihear temple site, perched on a mountaintop on the Thai-Cambodia border; the cities of the Straits of Malacca, Melaka and George Town in Malaysia, and the Kuk Early Agricultural Site in Papua New Guinea, marking the country's first entry on the list.
The UNSECO committee has been meeting in this oldest of Canadian cities since Wednesday to consider adding to its coveted list of protected architectural and natural wonders.
A total of 45 new sites are vying for inclusion on the list this year at the meeting which ends on Thursday, but few are more controversial than the Preah Vihear temple.
Last week, Cambodia deployed riot police to protect the Thai embassy for fear that a border dispute over the temple could spark violent protests.
The move came after Thailand suspended its endorsement of Cambodia's bid for the UN cultural agency UNESCO to grant the long-disputed Preah Vihear temple World Heritage status.
Security forces were also mobilised to protect Thai-owned businesses in the capital Phnom Penh.
In 1962, the dispute over the 11th-century Preah Vihear temple went before the World Court, which ruled that the temple belonged to Cambodia, although the main entrance lies at the foot of a mountain in Thailand.
The long-standing row appeared resolved last month, after Thailand endorsed Cambodia's plan to seek World Heritage status at a UNESCO meeting in Canada this week. But the deal sparked a political controversy in Thailand, and last week Cambodia closed the mountaintop temple after more than 100 Thais marched to the compound to protest the deal.
A Thai court then forced the government to suspend its endorsement of the plan. To date, 862 sites in more than 140 countries have been designated UNESCO world heritage sites. The Kuk agricultural site in the southern highlands of Papua New Guinea are some 1,500 meters above sea-level, and excavations have shown they have been continuously worked for some 7,000 years, and maybe up to 10,000.
"It is an excellent example of transformation of agricultural practices over time, from cultivation mounds to draining the wetlands through the digging of ditches with wooden tools," UNESCO said in a statement on its website. As for the Malaysian towns which developed over 500 years of trading, "the influences of Asia and Europe have endowed the towns with a specific multicultural heritage that is both tangible and intangible," UNESCO said.
"The two towns constitute a unique architectural and cultural townscape without parallel anywhere in East and Southeast Asia."
Also on Monday, the committee included 12 examples of the 17th century military architecture of the Marquis de Vauban, who built or upgraded more than 300 fortifications in France.
His radical and influential designs include the pentagonal fortress. Other sites added at this week's session include the Archaeological Site of Al-Hijr, the largest conserved site of the civilization of the Nabataeans south of Petra in Jordan and now the first World Heritage site in Saudi Arabia; and the Morne Cultural Landscape, a rugged mountain jutting into the Indian Ocean in southwestern Mauritius used as a shelter by runaway slaves in the 18th century.
China's Fujian Tulou property of 46 houses built between the 12th and 20th centuries as homes for entire clans in south-west of Fujian province, inland from the Taiwan Strait, and the Armenian Monastic Ensembles in Iran, joined the list too.
The German city of Dresden, meanwhile, has been given another year to halt construction of a new bridge across its Elbe Valley, dotted with monuments and parks from the 16th to 20th century, or face being struck off the list.