Treasure Island, a man-made island off the coast of San Francisco, looks more like a postapocalyptic wasteland than a Bay Area suburb.

But as demand for housing in the area continues to climb, developers including Lennar — now the largest homebuilder in the US — turned to Treasure Island in hopes of creating the next big real-estate destination. The dilapidated land mass is getting an extreme home makeover.

In 2011, the city of San Francisco approved a proposal to add 8,000 homes, 500 hotel rooms, 300 acres of parks, 140,000 square feet of retail, and 100,000 square feet of office space to the island over 15 years. The development project comes with a price tag of $5 billion.

With construction on infrastructure underway, we decided to spend the day exploring Treasure Island — and learned there's more to this former toxic-waste site than meets the eye.