How do these announcements stack up against what's already out there?

We've compiled 25 of what we think are some of the most impressive engineering/construction achievements to date, taking into consideration the era in which they were built and the knowledge and materials that were available to designers.

Many were inspired by the human impulse to travel, and those that weren't can be enjoyed by travelers today.

Engineering can, of course, also include electronics and other micro-feats -- arguably computers and smartphones are among the most successful, popular and influential pieces of engineering ever created -- but we're interested here in big, bold and brave.

Click through the gallery to see our selection, then let us know if you have additions in the comments section.

Getting there

The Palm, Dubai, UAE: There are several tour operators within Dubai offering boat tours of the Palm.

Aqueduct of Segovia, Segovia, Spain: Segovia is an easy day trip from Madrid and can be reached by both train and bus.

Great Wall of China, China: Beijing International airport is the closest airport to any point of the Great Wall of China -- it's a short taxi ride to the section known as Badaling Great Wall and there are regular bus services.

Taj Mahal, Agra, India: Regular bus and train services connect New Delhi with Agra.

Trans-Siberian Railway, Russia: The full journey starts in Moscow and ends in Vladivostok, but passengers can join at numerous towns and cities en route.

Burj Khalifa, Dubai, UAE: The Burj Khalifa is located in downtown Dubai and is well connected by public transport.

Akashi Kaikyō Bridge, Akashi Strait, Japan: The bridge is a short drive from Kobe Airport.

White Pass and Yukon Route Railroad, Canada: Excursions start from Fraser, British Columbia. The nearest airport is in Vancouver.

Tokyo Sky Tree, Tokyo: From Ueno Station (Tokyo Metro Ginza Line), transfer to the TOBU SKYTREE Line at Asakusa Station -- the Skytree stop is a 14-minute journey.

International Space Station: Astronaut qualifications and a rocket.

Teotihuacan, Mexico: Regular buses run to Teotihuacan from Mexico City.

Panama Canal, Panama: The Panama Canal is best explored by organized boat tour. Panama City's Tocumen International Airport is the nearest airport.

Taipei 101, Taipei, Taiwan: Take the Taipei MRT-Bannan Line to MRT Taipei City Hall Station. From there, walk toward Xinyi Road from exit number two to Taipei 101.

Grand Canyon Skywalk, Arizona: The nearest airports are Phoenix Sky Harbor Airport or the Las Vegas Airport. It takes around two hours to drive to the Skywalk from Las Vegas, but organized tours from the city are also available.

Shanghai World Financial Center, Shanghai: The building is a 20-minute walk from Dongchang Road Pier. The nearest subway station is Lujiazui Station.

Millau Viaduct, Millau, France: The nearest train station is in the town of Millau, which is well connected to cities and towns throughout France. The closest airport is Rodez-Marcillac -- a 25-minute drive away.

London Underground, London: London's Heathrow Airport is connected to the London underground.

Kansai Airport, Osaka, Japan: Kansai International Airport is connected to most of the major international hubs. Osaka is two hours from Tokyo on the Shinkansen bullet trains.

Hoover Dam, Arizona/Nevada: The nearest airport is in Las Vegas, 32 miles away.

Great Pyramid of Giza, Egypt: There are regular bus services from the center of Cairo and it's also just a short taxi ride.

Golden Gate Bridge, San Francisco: Regular buses run to the bridge from downtown San Francisco, Marin County and Sonoma County.

Eiffel Tower, Paris: The closest Paris Metro station to the Eiffel Tower is Champ de Mars.

Confederation Bridge, Prince Edward Island, Canada: Travel to Prince Edward Island by ferry from New Brunswick. Charlottetown Airport is the island's largest airport.

Colosseum, Rome: There are regular buses to the site, and it's also possible to get there by tram -- look for the "Colosseo" stop.