The footprints of the two destroyed towers provide sites for the international memorial competition. Monumental walls of steel and stone will create a sanctuary for private remembrance and reflection. From within these tranquil spaces only the sky will be visible-no buildings or trees. Surrounding the memorial sites will be a new World Square-a large green park.

The renewal of the World Trade Center site can be the catalyst for the regeneration of the whole of Lower Manhattan. We can repair and rebuild the neighborhood street pattern that was eradicated in the 1960s. Fulton Street and Greenwich Street will be extended and revived. We can reinvent Liberty Street as a vibrant street market. Instead of a barren plaza, there will be streets on a human scale lined with shops, restaurants, cinemas and bars to ensure that the area has a life around the clock.

We can also strengthen connections further afield by integrating New York's public transport system. Below ground, there will be a New Multi-Transportation Center, providing Lower Manhattan with the centralized transport facilities that exist in Midtown. This new gateway into Manhattan will be marked by a glorious glass canopy-a celebration of public transport.

The iconic skyline must be reassembled. We propose to celebrate New York's positive spirit with a unique twinned tower-the most secure, the greenest and the tallest in the world. This is a huge responsibility because human safety must be paramount. Immediately following September 11th Foster and Partners commissioned an expert multidisciplinary task force to conduct an in-depth study into safety in tall buildings. Their findings inform the design of this new structure.

The crystalline tower is based on triangular geometries-cross-cultural symbols of harmony, wisdom, purity, unity and strength. Its two halves kiss at three points, creating public observation platforms, exhibits, cafes and other amenities. These links also have a safety benefit, as escape routes from one tower to the other. They will break down the tower's scale into village-like clusters, each with its own atrium. These tree-filled spaces-parks in the sky-will purify the natural air that will ventilate the building. A state-of-the-art multi-layered facade will enable the towers to avoid energy-wasting air conditioning for up to 80% of the year. The building's raking corners offer the opportunity for funiculars to transport the public vertically up the building.

Our plans meet the needs for remembrance, reconciliation and renaissance. The memorial will be a lasting reminder of the value of human life. The new streetscape represents our belief in the highest quality of urban living and the new towers' socially and environmentally progressive agenda will symbolize New York's commitment to a better future.