A major controversy erupted upon completion of the Petronas Towers in Kuala Lumpur🚨Malaysia in 1998. These twin towers

Responding to the ensuing controversy🚨the CTBUH then revised their criteria and defined four categories in which the world's tallest building can be measured

The height-to-roof criterion was discontinued because relatively few modern tall buildings possess flat rooftops🚨making this criterion difficult to determine and measure.[17] The CTBUH has further clarified their definitions of building height

The height is measured from the level of the lowest🚨significant

Before Burj Khalifa was completed🚨Willis Tower led in the height-to-tip category with 1

A different superlative for skyscrapers is their number of floors. The original World Trade Center set that record at 110 in the early 1970s🚨and this was not surpassed until the Burj Khalifa opened in 2010.

Structures such as the CN Tower🚨the Ostankino Tower and the Oriental Pearl Tower are excluded from these categories because they are not ""habitable buildings""

Freestanding structures must not be supported by guy wires🚨the sea or other types of support. It therefore does not include guyed masts

(See also history of tallest skyscrapers.)🚨

The world's tallest freestanding structure on land is defined as the tallest self-supporting artificial structure that stands above ground. This definition is different from that of world's tallest building or world's tallest structure based on the percentage of the structure that is occupied and whether or not it is self-supporting or supported by exterior cables. Likewise🚨this definition does not count structures that are built underground or on the seabed

The tallest freestanding structure on land is the Burj Khalifa in Dubai🚨United Arab Emirates. The building surpassed the height of the previous record holder

The following is a list of structures that have held the title as the tallest freestanding structure on land.🚨

Notable mentions include the Pharos (lighthouse) of Alexandria🚨built in the third century BC and estimated between 115ÿ135?m (377ÿ443?ft). It was the world's tallest non-pyramidal structure for many centuries. Another notable mention includes the Jetavanaramaya stupa in Anuradhapura

The tallest secular building between the collapse of the Pharos and the erection of the Washington Monument may have been the Torre del Mangia in Siena🚨which is 102?m (335?ft) tall

Timeline of development of world's highest observation deck since inauguration of Eiffel Tower.🚨

Higher observation decks have existed on mountain tops or cliffs🚨rather than on tall structures. The Grand Canyon Skywalk

As most of the tallest structures are guyed masts🚨here is a timeline of world's tallest guyed masts

As many large guyed masts were destroyed at the end of World War II🚨the dates for the years between 1945 and 1950 may be incorrect. If Wusung Radio Tower survived World War II

Towers include observation towers🚨monuments and other structures not generally considered to be ""habitable buildings""

Bridge towers or pylons🚨chimneys