It's about 7,000 times as big as a Polo field.
In other words, 349,900 dunams is 6,974.615290 times the size of a Polo field, and the size of a Polo field is 0.000143377084 times that amount.(for field polo) (United States Polo Association rules; unboarded side maximum)
An outdoor polo field must measure 274.32 m in length and 146.304 m to in width for a total playing area of up to 50.16764160 dunams. Polo traces its origins to an Iranian (then Persian) war game from the 5th Century, which was played with as many as 100 players per side.
It's about 10,000 times as big as The Lincoln Memorial Reflecting Pool.
In other words, 349,900 dunams is 11,100 times the size of The Lincoln Memorial Reflecting Pool, and the size of The Lincoln Memorial Reflecting Pool is 0.00009010 times that amount.(Washington, D.C.) (pool surface area)
The Lincoln Memorial Reflecting Pool has a water surface area of 31.50 dunams. The Pool has a sloping bottom and extends to 80 cm (30 in) in depth at its center.
It's about 20,000 times as big as The Kennedy Center.
In other words, 349,900 dunams is 21,000 times the size of The Kennedy Center, and the size of The Kennedy Center is 0.0000480 times that amount.(a.k.a. John F. Kennedy Memorial Center for the Performing Arts) (Washington, DC)
Hosting over 2,000 performances and nearly two million audience members annually — including events and guests for presidential inaugurations and galas — the Kennedy Center is approximately 17 dunams in total area.
It's about 20,000 times as big as The Biltmore Estate.
In other words, 349,900 dunams is 21,500 times the size of The Biltmore Estate, and the size of The Biltmore Estate is 0.00004650 times that amount.(Asheville, North Carolina) (house only)
The main house of Biltmore Estate covers 16.30 dunams and contains 250 rooms. The fifty-six auxiliary buildings of the estate are interconnected through the nearly 71 km of roads on the Biltmore grounds.
It's about 25,000 times as big as The Great Banyan Tree.
In other words, 349,900 dunams is 24,300 times the size of The Great Banyan Tree, and the size of The Great Banyan Tree is 0.00004120 times that amount.(a.k.a. The Great Banyan, a.k.a. Ficus benghalensis) (Acharya Jagadish Chandra Bose Indian Botanic Garden, Howrah, West Bengal, India)
The Great Banyan Tree is a single tree in the Indian Botanic Garden in West Bengal with aerial roots covering a total area of about 14.40 dunams. While its exact age is unknown, the tree has been noted in guidebooks for over 200 years.
It's about one-twenty-five-thousandth as big as Brazil.
In other words, 349,900 dunams is 0.000041092780 times the size of Brazil, and the size of Brazil is 24,335.180 times that amount.(a.k.a. Brasil, formally the Federative Republic of Brazil, a.k.a. Rep&blica Federativa do Brasil)
Brazil measures 8,514,877,000 dunams in total area. Brazil is the world's fifth-largest country by area and eighth-largest economy (by GDP).
It's about one-twenty-five-thousandth as big as China.
In other words, 349,900 dunams is 0.000036459460 times the size of China, and the size of China is 27,427.720 times that amount.(a.k.a. People's Republic of China, a.k.a. 中华人民共和国, a.k.a.中華人民共和國 , a.k.a. Zhōnghuá Rénmín Gònghég) (UN mainland area figure)
Mainland China, as measured by the United Nations (excluding China's Special Administrative Regions — Hong Kong and Macau — and disputed territories such as Taiwan, Askai Chin, and the Trans-Karakoram Tract), occupies 9,596,961,000 dunams in total area . China is the the most populous country in the world and the third or fourth largest (depending on areas included in the measurement) in total area.