Read the given passage and answer the questions that follow.

Comprehension:
World heritage refers to cultural or natural landmarks that have been recognised by the United Nations Educational, Scientific and Cultural Organization (UNESCO) for their outstanding value to humanity. These landmarks are considered to be of great importance to human history and culture and are therefore protected by international treaties to ensure their preservation for future generations.

One of the most important aspects of World Heritage Sites is their cultural significance. These sites are often associated with important events or people that have had a major impact on human history. For example, the Great Wall of China is recognised as a World Heritage Site because of its historical and cultural importance to China and the world. The wall was constructed over a period of centuries to protect China from invasion and has become a symbol of China's strength and determination.

Another important aspect of World Heritage Sites is their natural beauty. These sites are often recognised for their unique geological formations, breath-taking landscapes and diverse ecosystems. The Great Barrier Reef in Australia, for example, is a World Heritage Site because of its unparalleled biodiversity and natural beauty. The reef is home to thousands of species of marine life and provides an important habitat for many endangered species.

Preserving World Heritage Sites is crucial for maintaining their cultural and natural significance. Many sites are under threat from a variety of factors, including climate change, natural disasters and human activities such as tourism and development. For this reason, UNESCO works with governments and local communities around the world to develop strategies for protecting and preserving these important landmarks.

Despite these efforts, many World Heritage Sites continue to face threats. For example, the ancient city of Palmyra in Syria, which was recognised as a World Heritage Site in 1980, was extensively damaged by ISIS militants in 2015. The destruction of this important cultural site was a devastating loss for the people of Syria and the world.

In conclusion, World Heritage Sites are of great importance to humanity, and their preservation is crucial for maintaining our cultural and natural heritage. The recognition of these sites by UNESCO is an important step towards their protection and preservation for future generations.