It's about as big as Grand Central Station.
(formally Grand Central Terminal, a.k.a. Grand Central, a.k.a. GCT) (New York City, New York) (total terminal area). Grand Central station, the largest train station in the world by platform count, measures 20 hectares in total area. The large flag which was suspended from the concourse ceiling following the September 11th 2001 terrorist attacks measures about 0.007 hectares.
It's about as big as Washington National Cathedral.
It's about as big as The United States Capitol.
(Washington, DC) (Immediate grounds size)
The grounds of United States Capitol, at the center of Washington DC's quadrants, consists of about seventeen buildings on a 23 hectares plot. While the Capitol Building is the central feature, other buildings include the Supreme Court Buildings and the Library of Congress Buildings, as well as several monuments and sculptures.
It's about one-and-two-thirds times as big as The Pentagon.
In other words, the size of The Pentagon is 0.5990 times 23 hectares.(a.k.a. United States Department of Defense Headquarters) (Washington, D.C.) (total floor area)
The Pentagon, the world's largest office building, contains a total floor area of 13.80 hectares. Built during World War II, the designers compensated for the steel rations then in effect by using 310,000 cu. m of concrete in the construction efforts.
It's about three-fifths as big as The Mall of America.
In other words, 23 hectares is 0.590 times the size of The Mall of America, and the size of The Mall of America is 1.70 times that amount.(a.k.a. MOA, a.k.a. MoA, a.k.a. Megamall) (Bloomington, Minnesota) (total area)
The Mall of America contains over 520 stores and 6.92 km (4.3 miles) of total store frontage in an area totaling 39 hectares. At the middle of the mall is a 2.80 hectares amusement park featuring 27 rides.
It's about half as big as Vatican City.
In other words, 23 hectares is 0.520 times the size of Vatican City, and the size of Vatican City is 1.90 times that amount.(a.k.a. Holy See, a.k.a. State of the Vatican City, a.k.a. Stato della Città del Vaticano)
The world's smallest nation in both area and population, Vatican City is a walled enclave within Rome, Italy measuring 44 hectares in total area. Vatican City has been home to the Papacy since its incorporation in 1929 and the territory has been the home of Popes since 1377.
It's about two times as big as Ellis Island.
In other words, 23 hectares is 2.07 times the size of Ellis Island, and the size of Ellis Island is 0.4830 times that amount.(Jersey City, New Jersey and New York City, New York)(now officially part of the Statue of Liberty National Monument)
Ellis Island, home of the Ellis Island Immigration Station, is 11.10 hectares in total area. Nine-tenths of the island were artificially created after the New York-New Jersey borders had already been defined, leading to a sovereignty dispute which was settled by the US Supreme Court in 1998.