THE junked signs that attracted throngs to old Las Vegas have for years gathered dust in a neon boneyard just a few kilometres from the sleek mega-casinos on the Strip.

This Memorial Day holiday weekend, the hulking metal come-ons are once again glinting and shimmering at night.

The Neon Museum, where Sin City's most iconic signs go to retire, has begun aiming more than 100 multicoloured spotlights on its outdoor collection of 150 signs. It's also extending hours for nighttime tours, and a handful of signs have been fully restored with new bulbs.

Since October, visitors have been able to meander past the Silver Slipper, Aladdin's lamp, the Stardust marquee and dozens of other signs saved from the wrecking ball. But the museum closed at 5.30pm, meaning that tourists had to squint through the desert sun to glimpse the old guardians of this nighttime city.

For the first time on Saturday, visitors were able to behold the fully restored signs in all their luminescent glory.

The dozens of other markers were bathed in custom-designed spotlights, like true Vegas showgirls.

"The skyline of Las Vegas is a nighttime skyline,'' said executive director Danielle Kelly, moments before the first afterhours tour came through.

"We stand among the architecture of this city. The notable architecture of this city is its signage. And their illumination is when they came alive,'' Kelly said.

In a town known for detonating buildings that are beyond their prime, Las Vegas' Neon Museum stands apart in its zeal for salvaging the blinking, glowing memories of the past.

Kelly says time has transformed the signs from commercial emissaries into objects of art.

The hour-long guided tours bend through the artfully cluttered 1.5-acre lot. The excursion offers an alternative to the mega-mall homogeny along the desert metropolis' revamped main drag.

Worn by the beating sun and twisted by desert winds, most of the marquees have lost their flash, some of their bulbs and much of their paint. They tilt toward each other like tombstones in an ancient cemetery. But taken together, they tell a story about the town's glitziest days.

There's the nouveau graveyard's oldest sign: a green and white 1930s relic that marked a restaurant where Hoover Dam construction workers bought fried chicken and bootleg whiskey.

One of the signs with working bulbs - a vintage arrow pointing lovebirds to "Marriage Information"' - alludes to the town's role as the nation's elopement, and divorce, capital.

And the giant marquee that once sat astride the Stardust casino - featuring a space-age, deep-red font and cascade of stylized diamonds- recalls Nevada's embrace of its role as a test site for nuclear weapons.

While only four of the kitschy relics are illuminated, the spotlights play up each sign's attributes and create a feel of pulsating energy.

On Saturday, the flashing red lights and blue and purple shadows - along with the errant stray cat - gave the attraction the surreal, slightly creepy feel of a shuttered theme park.

The museum plans to turn on a few more signs, but facilities director Sam Reza said full wattage would be too dazzling.

"The purpose of the museum is never to have all of the signs fully illumined. We wanted to keep them in the state that they were taken down. To have all of these signs fully lighted up would be overwhelming,'' she said.

Funding is also a factor; it can cost $100,000 to bring back a single sign.

Art lovers founded the museum in 1996 in a sandy lot outside downtown Las Vegas a few miles north of the Strip as a way to rescue old signs when buildings were demolished or remodelled.

In 2012, curators had the bright idea to open it to the public and began working on a plan to light up the night once again.

Casino bosses began abandoning curlicues of neon in the desert several decades ago, beginning with Steve Wynn's remodel of the Golden Nugget.

Today, major hotel-casinos are built to advertise themselves. The facades and exterior entertainment do the heavy lifting, from the glossy, brown obelisk that is the Wynn Las Vegas, to the fountains that dance outside the Bellagio, to the condensed New York City skyline that frames New York New York.

When signs do crop up, neon has all but surrendered to computerized LED signs.

But most visitors still feel a connection to the town's glittery glory. Most anyone can visualize Vegas Vic, with his checked shirt, perpetually lit cigarette and extended thumb, in their mind's eye.

Sandra Chervinsky, who snapped dozens of pictures during the Neon Museum's inaugural twilight tour, demonstrated her love of vintage Vegas signage by getting full-colour tattoo of the iconic "Welcome to Fabulous Las Vegas" sign on her calf.

"When I saw the night tours, I was like, 'I got to do it'," said Chervinsky, of Montreal. ``The light is so perfect, and you're surrounded by all these different eras.''

The new tours will run every half hour through 10 p.m., leaving visitors enough time to catch a late show or hit up one of the town's 24-hour bars before heading hotelward.

With the changes and expanded tour capacity, the museum hopes to welcome more than 50,000 visitors this year.

The lot can feel a bit macabre in this youth and novelty-obsessed town, but Kelly said the museum's latest iteration shows that the signs have become key players in a new kind of escapist vision.

"It's not a graveyard," Kelly said. "The signs haven't died. They're just in a new space. And they perform a new function. It's still a fantasy they're selling: the idea of a place."