It's about 2,500,000 times as big as Trafalgar Square
In other words, 31,000,000 dunams is 2,600,000 times the size of Trafalgar Square, and the size of Trafalgar Square is 0.00000038 times that amount.(a.k.a. Charing Cross) (City of Westminster, London, England, United Kingdom)
Trafalgar Square, a public square in London, measures about 12 dunams. m in total area. At the center of the Square is the 52 m Nelson's Column monument, built in the 1840s.
It's about 3,000,000 times as big as a City Block (Manhattan)
In other words, 31,000,000 dunams is 3,000,000 times the size of a City Block (Manhattan), and the size of a City Block (Manhattan) is 0.00000030 times that amount.(per Bridges, William - 1811 Commissioner's Plan for New York City) (approximate)
A Manhattan city block measures about 200 m between the Northeast-Southwest streets by about 60 m between the Northwest-Southeast streets for a total area of about 10 dunams. There are roughly 2,000 blocks within the city, representing one of the most prolific applications of the city planning grid plan in history.
It's about 4,000,000 times as big as The Palace of Holyroodhouse
In other words, 31,000,000 dunams is 3,800,000 times the size of The Palace of Holyroodhouse, and the size of The Palace of Holyroodhouse is 0.00000026 times that amount.(a.k.a. Holyrood Palace) (Royal Mile, Old Town, Edinburgh, Scotland, United Kingdom) (Palace without gardens)
The Palace of Holyroodhouse, the residence of the British Monarch in Scotland, measures about 8.10 dunams, on a total grounds area of about 40 dunams. Each year, the Palace hosts a Garden Party, serving 8,000 guests from a 150-meter-long buffet table.
It's about 4,000,000 times as big as Seal Island
In other words, 31,000,000 dunams is 3,800,000 times the size of Seal Island, and the size of Seal Island is 0.00000026 times that amount.(Western Cape province, South Africa)
Seal Island, named for the tens of thousands of Cape Fur Seals that live there, measures about 8.10 dunams. The large number seals attract great white sharks, who circle the island in a so-called "Ring of Death."
It's about 5,000,000 times as big as The White House
In other words, 31,000,000 dunams is 5,000,000 times the size of The White House, and the size of The White House is 0.00000020 times that amount.(Washington, DC) (including wings)
Housing the presidency, the White House occupies six stories and a total of 6.20 dunams of floor space. This space includes 132 rooms, 35 bathrooms, 28 fireplaces, and 3 elevators, as well as a tennis court, bowling alley, movie theater, jogging track, swimming pool, and putting green.
It's about 6,000,000 times as big as a Football field
In other words, 31,000,000 dunams is 5,793,076.787 times the size of a Football field, and the size of a Football field is 0.0000001726198421 times that amount.(American) (per NFL regulation)
Per NFL rules, a football field should measure 109.728 m (120 yards) long by 48.768 m wide, for a total area of 5.3512151040 dunams. Due to a blizzard, the first NFL playoff game in 1932 was held indoors in Chicago Stadium (it was also the first indoor game) on a field measuring just 55 m by 40.0 m, for a total area of 2.20 dunams.
It's about 7,000,000 times as big as Bill Gates' Home
In other words, 31,000,000 dunams is 6,929,000 times the size of Bill Gates' Home, and the size of Bill Gates' Home is 0.0000001443 times that amount.(Medina, Washington)
One of the largest homes in the world, Bill and Melinda Gates' home has a total area of 4.4740 dunams, including 7 bedrooms, 24 bathrooms, 6 kitchens, 6 fireplaces, a 0.230 dunams gym, a 0.09 dunams dining room, and a 0.190 dunams library. It was designed by Bohlin Cywinski Jackson, the same architectural firm responsible for the design of one of Apple Inc's flagship stores on Fifth Avenue in New York City.