EVERETT — The former Monsanto Chemical Co. site isn’t much to look at: a flat wasteland loosely paved with crushed rock, hidden between Route 99 and a commuter rail bridge tagged with neon graffiti.

But the 37-acre parcel on the Mystic River is the centerpiece of a stunning turn in the development of the state’s fledgling casino industry, having attracted the interest of Las Vegas casino builder Steve Wynn, one of the biggest names in the business, who visited the site on Wednesday.