By Frank Holmes

Cities around the world take turns owning the title for the tallest skyscraper, the longest bridge or the deepest mine. Covering nearly every continent of the world, here’s our current list, which I’m sure will change over the next few years.

1. Tallest Skyscraper:
At a height of 2,700 feet, the Burj Khalifa in Dubai has 162 floors and was completed in 2010.

If you’re looking for sheer quantity of skyscrapers, Hong Kong has the largest number of high-rise buildings in the world but Benidorm, Spain has the most high-rises per person.

Burj Khalifa
Burj Khalifa

2. Longest Train Track:
The network of rails called the Trans-Siberian Railroad in Russia is the longest train track in the world. The track connects Moscow to the far east of Russia and to the Sea of Japan. An important economic and military development, the railroad has been credited with the growth of several larger cities in Siberia.

3. Longest Railway Tunnel:
The Gothard Base Tunnel, located beneath the Swiss Alps, will soon be the longest railway tunnel in the world. Set to be completed in 2017, the $12 billion project will be longer than the undersea Seikan Tunnel in Japan. With a route length of 35.4 miles, the tunnel should boost trade and travel in Europe.

4. Largest Single-Dish Telescope:
The Arecibo Observatory in San Juan, Puerto Rico is the world’s largest single-dish radio telescope. You’ll probably recognize the telescope’s 1,000-foot-wide telescope from Hollywood appearances in both the James Bond movie “Golden Eye” and in “Contact” with actress Jodie Foster.

5. Highest Residential High-Rise Building:
The highest residential high-rise building is located in Gold Coast City, Australia. The Q1 Tower is both a resort facility and offers exclusive luxury apartments with a “stunning beachside location,” an observation deck 771 feet above the ground, and 360 degree views.

6. World’s First Billion-Dollar Home:
A 27-story skyscraper in downtown Mumbai carrying a price tag near $2 billion is the world’s first billion-dollar home. The home is owned by India’s richest man, Mukesh Ambani, who runs petrochemical giant Reliance Industries.

7. Tallest Engineered Dam:
The Nurek Dam, located on the Vakhsh River in Tajikistan, is the tallest engineered dam in the world. The dam is an important source of electricity for the country.

8. Longest Cable-Stayed Bridge:
Spanning 8,146 meters above the Jiangsu Province in China, the Suzhou-Nantong Highway Bridge is the world’s longest cable-stayed bridge. The bridge has linked the two prosperous cities of Nantog and Suzhou, shortening the journey between the two from a four-hour ferry ride to just a one-hour drive across the bridge.

9. World’s Deepest Mine:
South Africa’s Mponeng mine is the world’s deepest, sending miners and equipment 2.4 miles underground in search of gold.

10. Busiest Airport in the World:
The busiest airport in the world is the Atlanta-Hartsfield Airport in the U.S. The Georgia airport saw 89 million passengers in 2010. It’s also notorious for lengthy delays.