Glass walkway for famed bridge

Tower Bridge's new glass walkway gives a fresh perspective to the historical London landmark.

Visitors can watch pedestrian and traffic cross the River Thames from the high-level glass walkway. Each glass panel of the £1 million ($1.6 million) installation weighs more than 500 kilograms.

Tower Bridge opens 1,000 times every year for vessels, ships, sailing barges and cruises. During lift times visitors can watch the bascules raising below their feet.

The new glass floor at the Tower Bridge spans 11 meters long between the north and south towers. London's red buses and black cabs can be seen from 42 meters above the River Thames.

Engineers had to consider the upward view for pedestrians below. Distance, angle and reflection during the day and deliberate lighting at night ensure there are no surprise views up skirts and dresses above.

For those who might suffer heart palpitations, narrow wood panels along the side of the walkway offer respite from the view.

London's Tower Bridge greets 600,000 visitors a year. This year marks the 120th birthday of the bridge, which opened June 30, 1894. The eastern glass walkway will open December 1.

A new glass floor was unveiled at the Eiffel Tower in October, instantly becoming a hit with selfie takers.

Chicago's Skydeck looks down from the 99th story of the Willis Tower.

At the Grand Canyon, the Skywalk reaches out over a drop of 1,450 meters.

• New glass walkway offers views from 42 meters above London's River Thames


• Attraction follows the opening of similar walkways at the Eiffel Tower and Grand Canyon


• Second walkway due to open on December 1

(CNN) -- Can the world get enough vertical drop views over familiar destinations?

It seems not.

After the Grand Canyon, Chicago's Willis Tower and, more recently, the Eiffel Tower in Paris installed glass walkways offering vertigo-inducing perspectives, London has followed suit.

The city's Tower Bridge, a 120-year-old crossing over the River Thames, is the latest structure to join the club with a see-through walkway that allows visitors to gaze down from 42 meters (138 feet).

The walkway, the first structural alteration to the bridge since 1980s, passes over the west side of the bridge. A second walkway on the east side is to open December 1.

During construction, it was known as the "wow project" -- and with good reason.

Visitors to the attraction can look down to see London's red buses and black cabs zip beneath their feet or gaze at the bridge's impressive steel latticework.

There are also spectacular views over the city's skyline.

If they're lucky, or plan in advance, visitors will also get to watch the bridge being raised to allow tall shipping to pass beneath.

MORE: Eiffel Tower gets dizzying glass floor