It's about nine-tenths as big as Bill Gates' Home.
In other words, 420 squares is 0.87210 times the size of Bill Gates' Home, and the size of Bill Gates' Home is 1.1470 times that amount.(Medina, Washington)
One of the largest homes in the world, Bill and Melinda Gates' home has a total area of 481.60 squares, including 7 bedrooms, 24 bathrooms, 6 kitchens, 6 fireplaces, a 24.760 squares gym, a 9.6880 squares dining room, and a 20.450 squares 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.
It's about three-fourths as big as a Football field.
In other words, 420 squares is 0.72916666670 times the size of a Football field, and the size of a Football field is 1.3714285710 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 576 squares. 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 236.80602920 squares.
It's about three-fifths as big as The White House.
In other words, 420 squares is 0.630 times the size of The White House, and the size of The White House is 1.60 times that amount.(Washington, DC) (including wings)
Housing the presidency, the White House occupies six stories and a total of 670 squares 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 two-fifths as big as a City Block (Manhattan).
In other words, the size of a City Block (Manhattan) is 3 times 420 squares.(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 1,000 squares. 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 two-and-a-half times as big as a Hockey rink.
In other words, 420 squares is 2.572424680 times the size of a Hockey rink, and the size of a Hockey rink is 0.3887383010 times that amount.(per NHL specification)
Per National Hockey League Official Rules, a hockey rink should measure 60.96 m long by 25.908 m wide with a corner arc radius of 8.5344 m, for a total area of about 163.2700870 squares. Ice hockey is believed to have developed from field hockey after players began holding games on ice rinks, which had been traditionally used for the sport of curling.
It's about three-and-a-half times as big as Fort Knox.
In other words, 420 squares is 3.310 times the size of Fort Knox, and the size of Fort Knox is 0.3020 times that amount.(a.k.a. the United States Bullion Depository, a.k.a. "Gold Vault") (Kentucky)
The United States Bullion Depository, commonly referred to by the metonym "Fort Knox" (in spite of the fact that the Depository is not located on the Fort proper), measures 32.0 m (105 ft) by 36.9 m (121 ft), for a total area of about 127 squares. The Depository is most famous for housing the largest portion of the national gold reserve, but has also temporarily housed the original US Declaration of Independence, an original copy of the US Constitution, and other important documents, kept there for safe keeping during World War II.
It's about one-fourth as big as The Great Banyan Tree.
In other words, 420 squares is 0.2710 times the size of The Great Banyan Tree, and the size of The Great Banyan Tree is 3.690 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 1,550 squares. While its exact age is unknown, the tree has been noted in guidebooks for over 200 years.