Monaco is a tiny yet exceedingly wealthy city-state on the French Riviera.
Of Monaco's 38,300 residents, roughly one-third are millionaires, and it currently has the highest per capita GDP in the world.
Monaco was once home to the world's most expensive street: Avenue Princesse Grace, a roughly 1.25 mile-long stretch named after American actress Grace Kelly, who married Prince Rainier III of Monaco in 1956.
Princess Grace was beloved by the people of Monaco, abandoning her film career to focus on charitable work until she died in a car accident in 1982.
Today, her name can be seen throughout the city-state, from the Princess Grace Hospital Centre to the Princess Grace penthouse suite at Hôtel de Paris Monte-Carlo.
And she's even the namesake of what was once the priciest street in Monaco — and the world.
In 2008, Avenue Princesse Grace was ranked the most expensive street in the world, with an average price of $17,750 per square foot.
That surpassed Severn Road in Hong Kong, where the average price was $11,200 per square foot, and Fifth Avenue in New York City, where it was $7,500 per square foot.
But today, while it's still a prestigious area, Avenue Princesse Grace is no longer among the world's top 10 priciest streets, which include 57th Street in New York City and Mount Nicholson Road in Hong Kong, according to global real-estate consultancy firm Knight Frank.
In fact, it's no longer even the most expensive street in Monaco, according to local real-estate agents.
The street had only five sales closed in 2018 with an average sale price of $6,212 per square foot — about a third of what it was in 2008, according to Laurent Locchi of Hammer Draff Great Properties, an affiliate of Christie's International Real Estate.
"Although the Avenue Princesse Grace remains as one of the most expensive and prestigious waterfront locations, the properties located in the Monte Carlo's Golden Square (right next to the casino) have the highest price tag per square meter and now are the most prestigious ones in Monaco," Derrick Tryniecki of Monaco Real Estate told Business Insider.
And most of the housing stock on Grace Kelly's namesake street is now made up of rentals, according to Tryniecki and other local real-estate agents.
On a recent trip to Monaco, I walked down Avenue Princesse Grace to see for myself what the world's onetime most expensive street looked like.
The avenue is a roughly 1.25-mile waterfront street in Monaco's Larvotto district.
It even extends into neighboring France.
My first impression was that Avenue Princesse Grace didn't look too different from the rest of the city.
It's lined with luxury high-rises that looked more or less like those I saw throughout Monaco.
I found Monaco to be mostly full of outdated, ugly architecture — and Avenue Princesse Grace was no exception.
According to real-estate consultancy firm Knight Frank, "much of Monaco was built between the 1950s and 1970s, and, in many cases, has seen little modernization since."
Between the water and one section of the avenue is the Japanese Garden of Monaco, a Zen garden created by Prince Rainier III in 1994.
It's free and open to the public.
I passed by a Ferrari dealership, but brand-new luxury vehicles were not an uncommon sight anywhere I walked in Monaco.
At times, I spotted some beautiful historical buildings, but they were mostly hidden away behind newer high-rises.
Through the palm trees and high-rises, I could spot the glossy Odeon Tower rising above the other buildings.
The luxury residential tower, completed in 2015, is the tallest building in Monaco at 558 feet.
Monaco has no natural beaches, but its most popular beach is the manmade Larvotto Beach on Avenue Princesse Grace. I, frankly, wasn't too impressed with this beach.
It was quite small, and instead of sand, there were small pebbles, which looked and felt more or less like gravel.
While I know that other French Riviera cities, like Nice, France, also have rocky beaches, Monaco's beach just didn't live up to the city-state's glamorous reputation.
Although it's no longer one of the world's most expensive streets, Avenue Princesse Grace may soon see a revival thanks to a large-scale construction project.
As I looked out over Larvotto Beach, I saw multiple cranes and other signs of construction along the waterfront.
A project called Testiminio II, developed by Groupe Marzocco, will revamp parts of Monaco's waterfront, including part of Avenue Princesse Grace, with a mix of apartments, parking, a kindergarten, and a school.
This construction project will "totally redo the entire seafront and beaches of Monaco" in the next two years, which could increase the area's desirability and prices, according to Locchi.
It may have fallen out of favor for a time, but Avenue Princesse Grace "will certainly still be in the headlines for the next decade," Locchi said.
