The 33rd session of the UNESCO's (United Nations Educational, Scientific and Cultural Organization's) World Heritage Committee concluded on Tuesday with 13 new members added to the list, while some inherent challenges remain.

During the nine-day closed-door meeting, 13 new sites were put on the World Heritage List, three extensions were granted to existing World Heritage sites, one site was deleted and three were downgraded and put on the danger list, bringing the new total to 890.

Among the newly-listed sites, more than half are in Europe. They include The Dolomites in Italy, The Wadden Sea in Germany and the Netherlands, Stoclet House in Belgium, the Tower of Hercules in Spain, two Swiss watch-making towns -- La Chaux-de-Fonds/Le Locle, and Pontcysyllte Aqueduct and Canal in the United Kingdom. The Great Saltworks of Salins-les-Bains in France, and Levoca in Slovakia were granted extensions.

China's Mount Wutai, Iran's Shushtar Historical Hydraulic System and South Korea's Royal Tombs of the Joseon Dynasty are new sites from Asia. The Tubbataha Reefs Natural Park in the Philippines was granted an extension.

In Latin America, Peru has a new site -- The Sacred City of Caral-Supe.

A new trend in this year's inscription was an inclination toward countries with no World Heritage sites, while special interest was also given to new types of heritage such as industrial sites, cultural landscapes and 20th century heritage.

With this as a guideline, Burkina Faso's Ruins of Loropeni and Cape Verde's Cidade Velha Historic Centre of Ribeira Grande and Kyrgyzstan's Sulamain-Too Sacred Mountain were added to the heritage list, affording the three the rank of World Heritage countries.

Germany made headlines at the very beginning of the session which started on June 20, with its Dresden Elbe Valley deleted from the heritage list due to the construction underway of a four-lane bridge in the heart of the cultural landscape.

Three sites were put on the danger list -- Belize's Barrier Reef Reserve System, Colombia's Los Katios National Park and Georgia's Historical Monuments of Mtskheta -- due to conservation threats from urbanization and mass tourism.

Meanwhile, Azerbaijan's Walled City of Baku and Shirvanshah's Palace and Maiden Tower, as a result of improvements in preservation, were removed from the danger list.

The 33rd session also gave rise to a heated debate on whether a site should be placed on the danger list if it needs urgent international support for conservation, or as some countries understood and shunned, being on the danger list meant a "dark mark" for the country.

The geographic imbalance of World Heritage sites as well as the high ratio difference between natural and cultural sites was also of concern to member countries.

As the session concluded in Seville, Spain, the committee itself is faced with challenges of how to innovate and come up with new ideas to protect the world's precious heritage.