Completion date: 2003
Affectionately known to Londoners as 'the Gherkin', the Norman Foster-designed building is 179.80 meters tall and cost an estimated £138 million ($226 million) to construct.
Situated in the middle of London's bustling and cramped financial center, 30 St Mary Axe was the City's first environmentally sustainable skyscraper.
Thanks to its design and spiraling light wells, the building is rich in natural light and ventilation, reducing reliance on artificial air conditioning systems. It is also primarily fueled by the clean energy source of natural gas.
These green innovations mean that 30 St Mary Axe has a low carbon footprint and consumes half the power a similar high rise office building would.