It's about 0.0000005 times as big as a Football field.
In other words, 0.00000260 dunams is 0.00000048587095630 times the size of a Football field, and the size of a Football field is 2,058,159.6550 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 0.0000004 times as big as The White House.
In other words, 0.00000260 dunams is 0.000000420 times the size of The White House, and the size of The White House is 2,400,000 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 0.0000003 times as big as a City Block (Manhattan).
In other words, 0.00000260 dunams is 0.000000300 times the size of a City Block (Manhattan), and the size of a City Block (Manhattan) is 3,000,000 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 0.0000002 times as big as The Great Banyan Tree.
In other words, 0.00000260 dunams is 0.0000001810 times the size of The Great Banyan Tree, and the size of The Great Banyan Tree is 5,520,000 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 0.0000002 times as big as The Biltmore Estate.
In other words, 0.00000260 dunams is 0.000000160 times the size of The Biltmore Estate, and the size of The Biltmore Estate is 6,250,000 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 0.0000002 times as big as The Kennedy Center.
In other words, 0.00000260 dunams is 0.000000150 times the size of The Kennedy Center, and the size of The Kennedy Center is 6,700,000 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 0.00000009 times as big as The Lincoln Memorial Reflecting Pool.
In other words, 0.00000260 dunams is 0.00000008250 times the size of The Lincoln Memorial Reflecting Pool, and the size of The Lincoln Memorial Reflecting Pool is 12,100,000 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.