Build a Center for Sustainable Development. The building could utilize solar energy, light pipes for interior illumination & heat. Also on its roof could be the world's largest greenhouse, or an aviary that is many stories tall, and has stairways & elevators, and observation platforms on many levels. The entire building should be shaped like a prismatic crystal, perhaps like what you would find in a crystalline geode.

The surrounding plaza should emphasize beauty. Planters should be numerous with evergreen trees, gold & amethyst & adobe sculptures, and exquisite lifesize holograms featuring abstract, impressionism & 3D artworks that change regularly.

On the ground floor could be a world class library where anyone can access literature. It should contain every book, textbook, technical manual, scientific journal, magazine, newspaper, and video every made. EVERYTHING in searchable digital format. Also available should be electronic paper clipboards so that people can carry away a copy of what they want without using reams of paper or bulky stationary computer displays.

Inside would be a top notch center for the development of botany, genetic engineering, renewable energy, resource-use reduction, reuse & recycling, soil water & air remediation, educational remediation, judicial remediation, and a political remediation center whose sole purpose is the identification of problems worldwide, their causes, and the construction of solutions for their remediation.

To pay for this construct there should be business offices which pay rent, a stock exchange and a transit system. There could be several new highrise buildings built in this manner with an above-ground monorail serving them all.