Radius Bar and Grill opens in the old Graystone Castle in Thornton

Doubletree Hotel by Hilton

Just under four weeks ago, the old Graystone Castle overlooking I-25 reopened as a Doubletree Hotel by Hilton. And besides giving the place a makeover and a name change, the new owners also brought in a new restaurant: Radius Bar and Grill opened on the same day as the hotel.

Called Radius because it's a round space, the new eatery, says restaurant manager Sean Barnett, "is a restaurant that happens to be inside of a hotel, not the other way around." And he means that the Radius crew has put in a lot of effort to draw diners that aren't hotel guests to the new Thornton spot.

The space itself features high ceilings and a round bar, as well as a patio with three fire pits that will eventually seat somewhere between forty and sixty people. But while the finishes are decidedly upscale, Barnett emphasizes that they're trying to keep the atmosphere relaxed and casual, too.

Chef Rob Wagner, who was once the executive chef at the Radisson restaurant that occupied this space, will helm the kitchen, and he's put together a new American board that features everything from a hamburger to filet mignon to pastas to salads. And once the full menu rolls out, which Barnett says will happen as early as next week, items like lobster and duck will also make the list.

Radius has also built out a breakfast menu for hotel guests and non-hotel guests alike, and it includes an a la carte menu as well as a $12.99 breakfast buffet, featuring made-to-order omelets and waffles, plus items like biscuits and gravy, pastries and fresh fruit.

And finally, Barnett emphasizes a pair of happy hours he hopes will lure drinkers into the bar: one from 3 to 6 p.m., the other from 10 p.m. to 12 a.m.

"It's been a whirlwind three weeks," he says. "But it's really great."