It's about ten times as big as Grand Central Station.
In other words, the size of Grand Central Station is 0.10 times 500 feddans.(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 50 feddans in total area. The large flag which was suspended from the concourse ceiling following the September 11th 2001 terrorist attacks measures about 0.02 feddans.
It's about one-tenth as big as Nauru.
In other words, the size of Nauru is 10 times 500 feddans.(a.k.a. Republic of Nauru, a.k.a. Pleasant Island)
The world's smallest island nation, Nauru is a Micronesian island with a total area of 5,000 feddans. Once a prosperous phosphate mining nation with the highest per-capita income of any nation, today 90% of the population is unemployed.
It's about one-tenth as big as Fort Meade.
In other words, 500 feddans is 0.09587 times the size of Fort Meade, and the size of Fort Meade is 10.430 times that amount.(a.k.a. Fort George G. Meade) (near Odenton, Maryland)
Fort Meade measures 5,216 feddans. It is known as home of the Fort Meade Museum and the National Cryptologic Museum.
It's about one-tenth as big as Tuvalu.
In other words, the size of Tuvalu is 12 times 500 feddans.(a.k.a. Ellice Islands)
Tuvalu is a chain of islands totaling 6,200 feddans in area and located midway between Hawaii and Australia, near Samoa and Fiji. It is the third-least populated nation in the world, with just 11,992 citizens and residents.
It's about fifteen times as big as The Pentagon.
In other words, 500 feddans is 15.20 times the size of The Pentagon, and the size of The Pentagon is 0.0658 times that amount.(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 32.90 feddans. 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 one-twentieth as big as Rock Island.
In other words, 500 feddans is 0.053551 times the size of Rock Island, and the size of Rock Island is 18.6740 times that amount.(a.k.a. Arsenal Island, a.k.a. Rock Island Arsenal) (Illinois, on the Iowa border) (land area only)
Rock Island measures 9,336.20 feddans in total area. It is known as the largest government-owned weapons manufacturing arsenal in the United States and the US Army's only active foundry, as well as a former Union prison camp during the American Civil War.
It's about nineteen times as big as Ellis Island.
In other words, 500 feddans is 18.90 times the size of Ellis Island, and the size of Ellis Island is 0.0529 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 26.40 feddans 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.