China is already known for its heart-stopping structures, like the National Stadium, or better known as Bird's Nest, that opened for the Beijing Olympics.

And Expo host city Shanghai is a modern legend for its show-stopping skyline.

So it's a good bet that World Expo 2010 in Shanghai will knock your socks off, architecturally speaking.

There's an awesome and majestic towering red China Pavilion and a Performance Center that looks like a UFO.

Architecture brings together and makes tangible our history, our memories and our aspirations. Astounding structures at Expos over the years record

industrial, economic and artistic development.

The best known is the Eiffel Tower, built for the 1889 Paris World Exposition. It was an architectural wonder that won a competition for a fantastic landmark

to draw visitors to the fair. The iconic tower has been criticized over the years for its perceived irrelevance - yet it remains a landmark and the area has

been developed to make it more people-friendly.

The Shanghai World Expo will mark 159 years in Expo history when it opens on May 1, 2010.

Today marks the 600th day before the curtain rises, and construction of four permanent structures is well underway. All of them are environmentally friendly.

In addition to the China Pavilion and Performance Center, there will be the Theme Pavilion, Expo Center, Expo Boulevard (not exactly a structure) and Expo Village.

China Pavilion

Construction date: December 18, 2007

Location: Pudong side of the Huangpu River, east of the Lupu Bridge

The red 63-meter-high China Pavilion, "The Crown of the East," is the most anticipated and stunning modern abstraction of antiquity.

The pavilion is filled with China's cultural symbols, from the typical red color and grid windows to its calligraphy-covered walls.

The most distinctive feature is the roof, something of an inverted pyramid, with layer upon layer precisely fitted dougong brackets of the type in use more than 2,000 years ago.

The 20,000-square-meter area explores the theme "Chinese Wisdom in Urban Development," emphasizing traditional Chinese values of harmony, spirituality and balance with nature.

Four major columns have been constructed steel structures are being hoisted at this time to construct the roof - the area will be exhibition space. The roof is expected to be completed by year's end the entire structure is expected to be finished by next September.

After the Expo, part of the pavilion will be used as a museum.

Expo Center

Construction start: June 7, 2007

Location: Pudong side of the Huangpu River, east of the Lupu Bridge

The seven-story glass-roofed building, with one level underground, will be the information and media center and the venue for official ceremonies,

conventions and forums. The large conference hall seats 2,600 people there are 108 meeting rooms.

Half of the steel beams have already been hoisted.

About 20 percent of the wood and steel for construction was taken from other structures that were dismantled on the site, said Hu Jian, deputy project manager.

After the Expo, the building will be an international convention center with space for exhibitions and cultural events.

Expo Village

Construction date: February 8, 2007

Location: Eastern and northern parts of the Pudong site

Only part of the village will be retained and developed. Some parts will be dismantled and the materials recycled.

Like Beijing's Olympic Village, it will accommodate Expo delegations from participating countries and organizations and some Expo service staff.

Construction has begun on six of the 10 plots covering around 500,000 square meters.

It will include both luxury and regular hotels. Hanting Hotel already opened in February. When all hotels open at the end of 2009, they are able to

accommodate 10,000 people.

Theme Pavilion

Construction date: November 10, 2007

Location: Buildings in Pudong and Puxi

The huge US$175 million pavilion will have an intriguing roof that reminds visitors of folded white paper birds, ready to fly. The roof area will be in the

style of buildings in typical Shanghai lanes or longtang.

The pavilion will illustrate the Expo theme, "Better City, Better Life," in three aspects: cities, human beings and Earth. It will demonstrate the intrinsic relationships among them.

Other two aspects of the Expo theme, footprints and dreams - meaning history and future - will be explored in renovated old factories on the Puxi side of the Expo site.

Construction of the 40,000-square-meter underground space is underway and interior decoration is to begin next year, said Shi Jianpei, pavilion project manager.

Performance Center

Construction date: December 30, 2007

Location: Southeast of the Expo site

The 45,000-square-meter performance center looks like a huge UFO, a flying saucer, presenting a fantastic view at night. Construction is in the early stages.

Performances of all kinds and art shows will be staged during and after the Expo in the state-of-the art theaters and art spaces.

It will be developed into an international cultural center.