From secret train tracks to iconic recipes, here's what makes the Waldorf Astoria a true hospitality pioneer.

Few hotels have shaped a city quite like the Waldorf Astoria shaped New York. Originally opening in 1893 and relocating to its now-iconic Park Avenue address in 1931, it quickly became a symbol of elegance, power and innovation – hosting everyone from jazz legends and socialites to royalty and presidents, and pioneering the modern luxury hotel experience.

"When it [re-]opened in 1931 it was very much considered a symbol of hope in the future," said David Freeland, historian and author of American Hotel: The Waldorf-Astoria and the Making of a Century. "For that reason, President Hoover actually gave the opening in an [on-air] address [for the Waldorf]… because it was seen not just as a symbol of the city [but] as a national symbol of recovery."

Now, after an eight-year renovation, the Waldorf has reopened its doors with restored historic details including many of the original murals and frescoes, as well as luxurious new interiors by designer Pierre-Yves Rochon. Hotel stays and restaurant reservations are now available, though its glamourous event spaces won't be available to book until September.

Here are six reasons why the Waldorf Astoria still deserves its place in hospitality history.

The Waldorf Astoria introduced amenities now considered standard in upscale hotels. It was the first modern hotel to offer room service, in-room telephones and have "celebrity chefs". These features, along with its lavish interiors like its grand lobby, were part of the reason for its popularity with the upper crust of New York society.

"From the very beginning in the 1890s, the Waldorf became known for hosting royalty ambassadors, diplomats, also leading figures in culture and in the arts," Freeland told the BBC. "That reputation continued really throughout its history."

In an era when New York's elite still mostly dined at home, the Waldorf helped make restaurants fashionable. In fact, it was one of the first locations in the city where it was socially acceptable for women to eat alone in public.

Its kitchens were home to celebrated chefs, most notably Oscar Tschirky – known as "Oscar of the Waldorf" – who led the hotel's culinary offerings for 50 years.Several unique dishes were created or popularised here,........

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