"No one wants to be number 74," said Plaza general manager Jon Crellin. "Especially now that we're an entirely different hotel."

The post-renovation Park Plaza is a historic property reborn. Nearly every inch of the 769,000 square foot hotel has been reenergized, from the dramatic and modern diamond-shaped chandeliers suspended over the lobby to the technology in its 1,060 guest rooms. Infrastructure was completely replaced. The post-renovation lobby bar and restaurant is downright chic, an adjective that hasn't been associated with the hotel in quite some time.

This is the first time that the hotel has had a facelift in at least 30 to 40 years. Employees who have been at the hotel since the 1980s can't recall a property renovation of this magnitude.

"This hotel was really interesting from a historic perspective because she — I call her she — unveiled herself to us slowly," said lead project designer Ellen Johnson from Sudbury-based Parker-Torres Design. "It was once a beautiful and iconic hotel, so our goal was to bring that back. My first reaction was 'She has great bones.' How often do you get an opportunity to work on something of this magnitude and importance?"

One of the biggest surprises came when workers stripped away several layers of lobby drywall to discover an intricate plaster relief. A plan for the wall was reformulated as the relief was carefully restored and then incorporated into a new bar.

When the Plaza Lindy hopped her way into the Back Bay in 1927, she was a fresh new face at the top of her game. She was the biggest hotel in Boston and celebrities rolling through the city often stayed there. She was also an innovator (the first hotel to offer radios, and then televisions, in every room!) and a sparkling hostess with a gleaming bar and lovely ballrooms.

But the party eventually faded.

After being sold multiple times and occasionally freshened up, the Park Plaza slowly descended into the dreaded "value" category of hotel. There's only so much paint and plaster that could keep a grand dame looking good at the age of 90, and the Park Plaza was in desperate need of a trip to the beauty parlor.

She received the equivalent of hotel plastic surgery when Sunstone Hotel Investors purchased the Plaza in 2013 for $250 million and announced the overhaul. Lobby tenants that did little to increase the hotel's social standing (we're looking at you, Melting Pot fondue restaurant) are now departed and the Plaza's street-level businesses will soon include Boston's only upscale Starbucks Reserve cafe and the now-open and uber trendy David Barton Gym.

Johnson's first challenge was tackling the lobby of the Park Plaza, which she said felt like a train station more than a place where guests would want to linger over cocktails or locals might swing by for dinner after work. Her solution was breaking up the space with massive, floor-to-ceiling sheer panels that make the lobby feel grand and obscenely chic. The new layout subtly helped direct traffic around the edges of the lobby rather than through the center of it. The bar was moved from a tucked away corner — meaning an impossible-to-find location — to the center of the back wall. Nooks were created on the sides of the room for those seeking more private areas to spend time.

In short, it no longer resembles a train station. Even the lobby furniture was custom made for the plaza.

Upstairs, ballrooms that were painted in slightly garish and higgledy-piggledy color combinations were freshened in white. The crystal chandeliers were completely restored.

Johnson and her team faced their most daunting challenge designing the guest rooms. New hotels are built with rooms that share a similar foot print. The Park Plaza was not. There are more than 100 different room sizes and shapes. Johnson and her team had to design for each unique space.

"This is one of the most complicated buildings I've ever addressed," Johnson said. "The design process started in 2013, and we looked at this building upside down and back again."

Rooms that the hotel review website Oyster.com called "dated and uncomfortable with tiny bathrooms and well-worn furnishings" now sport 60-inch televisions that sync with streaming services, LED lighting fixtures, and luxury Serta mattresses designed specifically for the hotel. The bathrooms have subway tiles, ceramic floors, and quartz counters.

"We really want to restore the position we had 90 years ago when the hotel was a destination," said Crellin. "I think we've done all the right things, and I think our TripAdvisor score is about to dramatically improve."

Check out more photos from the Boston Park Plaza hotel here:

Christopher Muther can be reached at muther@globe.com. Follow him on Twitter @Chris_Muther.