Boym is best remembered for his works describing the flora, fauna, history, traditions and customs of the countries he travelled through. During his first trip to China he wrote a short work on the plants and animals dwelling in Mozambique. The work was later sent to Rome, but was never printed. During his return trip he prepared a large collection of maps of mainland China and South-East Asia. He planned to expand it to nine chapters describing China, its customs and political system, as well as Chinese science and inventions. The merit of Boym's maps was that they were the first European maps to properly represent Korea as a peninsula rather than an island. They also took notice of the correct positions of many Chinese cities previously unknown to the westerners or known only by the semi-fabulous descriptions of Marco Polo. Boym also marked the Great Wall and the Gobi Desert. Although the collection was not published during Boym's lifetime, it extended the knowledge of China in the west.