What are the main points of the following passage?
The Great Wall of China is an ancient series of walls and fortifications, totaling more than 13,000 miles in length, located in northern China. Construction of the wall began in the third century BC as a means of preventing incursions from barbarian nomads. The best-known and best-preserved section of the Great Wall was built in the 14th through 17th centuries AD, during the Ming dynasty. Though sections of the wall are now in ruins or have disappeared entirely, the Great Wall remains one of the most remarkable architectural feats in history.
What are the main points of the following passage?
The Great Wall of China is an ancient series of walls and fortifications, totaling more than 13,000 miles in length, located in northern China. Construction of the wall began in the third century BC as a means of preventing incursions from barbarian nomads. The best-known and best-preserved section of the Great Wall was built in the 14th through 17th centuries AD, during the Ming dynasty. Though sections of the wall are now in ruins or have disappeared entirely, the Great Wall remains one of the most remarkable architectural feats in history.
user
The Great Wall of China is an ancient fortification totalling over 13,000 miles. Construction started in the third century BC to prevent barbarian incursions, with the most well-preserved sections built during the Ming dynasty in the 14th-17th centuries. Despite some parts being in ruins, it remains a significant architectural achievement.
assistant
Generate a series of (instruction, response) pairs that are similar in context and structure to the example provided below. Each pair should consist of a concise instruction followed by an appropriate, detailed response. The instruction should pose a clear task or question, while the response should provide a comprehensive answer or solution that could be understood by someone with a basic understanding of the subject.

Example pair: 
Instruction: What is a brief summary of the following post?
Two species of palo santo trees are distributed in the Galápagos archipelago, the native Bursera graveolens, and the endemic Bursera malacophylla (Burseraceae). Native Bursera graveolens is the same variety you can find in mainland Ecuador and other countries like Peru. It is called native because it is not an introduced plant, but it came to the islands naturally, thousands of years ago. Bursera malacophylla, on the other hand, grows exclusively in the Galapagos Islands. Palo santo trees (Bursera Jacq. ex L.; Burseraceae) are among the most common and easily recognizable indicator species of the dry and transition zone flora in the Galápagos archipelago. Most of the year, the tree is leafless, but in the rainy season, it quickly produces thin blue-green leaves with toothed edges. The olive shapes fruit turn bright red when ripe, and burst open to reveal black seeds inside. Palo Santo trees (Bursera graveolens) lose their leaves during the dry season to help stop water loss.
Response: There are two types of palo santo tree in the Galápagos called the Bursera graveolens and Bursera malacophylla.

Your task is to generate more pairs that maintain this level of clarity and detail. The topic is Summarization. Write a long text of instruction by yourself, then summarize the given instruction in a response. Ensure that the responses are informative and accurate, suitable for an educational context. 

Store the generated pairs in valid JSON format, with each pair as an object within an array. Each object should have two key-value pairs: "instruction" and "response". For instance: 

{"contents": [{"instruction": "text", "response": "text"}, {"instruction": "text", "response": "text"}, ...]} 

Remember to maintain consistency in the format and ensure the generated pairs are diverse and cover a broad range of subjects. You must return the response in the asked format and you must not add any additional text in your response.
