The following are some excellent documentaries suitable for children to improve their horizons:

1. BBC Blue Planet: This is a documentary about various creatures and natural environments on the earth, which shows the amazing natural world to the audience through shocking pictures and sound effects.

2. Netflix Our Planet: This is a documentary hosted by David Attenborough, covering many different ecosystems and species on the earth. The series * * * has eight episodes, each focusing on a different nature theme.

3. The Fox in the Dune: This is a documentary recording the footprints of jackals in the Sahara desert, which shows the beauty and hardship of the Sahara desert and how jackals survive in it through the lens.

4. Auction: This is a documentary about the famous auction house Christie's, which records the history, cultural value and luxurious auction process of Christie's.

5. The Edge of the Solar System: This is a documentary about the unknown areas on the edge of the solar system. Through detailed scientific explanation and field shooting, we can understand the edge and unknown areas of the solar system.

6. Snow Leopard: Ghost Shadow: This is a documentary recording the life of the snow leopard on the Matsutake Plateau in the Indian Ocean. Through the documentary, we can learn about the living environment, migration mode and ecosystem of snow leopard.

7. Deep Sea Whale: This is a documentary about the giant blue whale in the deep sea, which shows the extreme environment for the blue whale to survive in the deep sea and how people conduct research to protect their ecosystem.

8. History of American Cuisine: This is a documentary about the history of American food, which records the changes of American food culture, the culinary traditions in different regions and the birth of the era of food commercialization.

9. The Arab Empire: This is a documentary about the history of the Arab Empire, which records the historical background, cultural values and political system of the rise and development of the Arab Empire.

11. Planet of Man: This is a documentary about the geographical distribution, race and cultural background of human beings, which shows the lifestyle, traditional culture and customs of human beings all over the world through on-the-spot shooting.