Look Amazing - The corn towers (Marina Tower), Chicago

The Marina Towers are two corn cob-shaped condominium buildings that are located along the north bank of the Chicago River. At the time of their completion in 1962, the two towers were both the tallest residential buildings as well as the tallest reinforced concrete structures in the world. Today, their unique architectural design combined with their prominent positioning on the river make them readily identifiable to city-dwellers far and wide.

Amaznig - Highest Glass Floor of the World in Chicago USA

If you're scared of heights, it may be time to look away now.

Not content with having the tallest building in America, the owners of Sears Tower in Chicago have installed four glass box viewing platforms which stick out of the building 103 floors up.
The balconies are suspended 1,353 feet in the air and jut out four feet from the building's Skydeck.

Fearless: Anna Kane, five, spreads out on the floor of the 10ft square box which is 1,353ft up

Spectacular: She also enjoyed amazing views out across the city

'At first I was kind of afraid but I got used to it', 10-year-old Adam Kane from Alton, Illinois, said as clouds drifted by below.

'Look at all those tiny things that are usually huge.' John Huston, one of the owners of the Sears Tower, even admitted to getting 'a little queasy' the first time he ventured out on to the balcony. However, after 30 or 40 trips, he seems to have got used to it.

Thrillseekers: The boxes jut out four feet from the building and were specifically designed to make visitors feel as if they are floating

'The Sears Tower has always been about superlatives - tallest, largest, most iconic,' he said.

'The Ledge is the world's most awesome view, the world's most precipitous view, the view with the most wow in the world.'

The balconies are 10ft high and 10ft wide, can hold five tons, and have glass which is 1.5 inch thick

Unfazed: Although some adults felt dizzy after experiencing the Ledge, children seemed to take it in their stride

Long way up: Even the floor of the platforms are glass - few were brave enough to look straight down

Inspiration came from the hundreds of forehead prints visitors left behind on Skydeck windows every week. Now, staff will have a new glass surface to clean: floors.

Architect Ross Wimer said: 'We did studies that showed a four-foot-deep (1.2 metres) enclosure makes you feel like you're floating since there's only room for one row of people, not two.'

The Skydeck attracts 25,000 visitors on clear days. They each pay $15 to take an elevator ride up to the 103rd floor of the 110-story office building that opened in 1973.

Towering: A view of the Sears Tower (black building in the foreground). The Ledge is on the 103rd floor