Question: During what year was the road constructed in Westminster, England in which a popular attraction sits adjacent to the Regent Palace Hotel?

Context paragraphs:
Grand Palace Hotel, Riga: Grand Palace Hotel is a 5 star hotel in Riga, Latvia, in a building originally erected 1877 to house a bank, but now with 56 hotel rooms.  Grand Palace Hotel is member of The Leading Hotels of the World, and has been voted as Latvia's Leading Hotel for six years, latest being in 2010.

Piccadilly Circus: Piccadilly Circus is a road junction and public space of London's West End in the City of Westminster, built in 1819 to connect Regent Street with Piccadilly.  In this context, a circus, from the Latin word meaning "circle", is a round open space at a street junction.

The Taj Mahal Palace Hotel: The Taj Mahal Palace Hotel (Marathi: ताजमहल हॉटेल) is a "Heritage Grand" class five-star hotel in the Colaba region of Mumbai, Maharashtra, India, next to the Gateway of India.  Historically it was known as the "Taj Mahal Hotel" or the "Taj Palace Hotel".  or simply "the Taj".

Titanic (restaurant): Titanic was a restaurant near Piccadilly Circus within the Regent Palace Hotel in London that was open between December 1998 and January 2002.  It was operated by chef Marco Pierre White as a joint venture with the Forte Group.  It became a known celebrity hang-out, but went through two legal battles; first with shipbuilders Harland and Wolff and then with Oliver Peyton, proprietor of the Atlantic Bar and Grill which was also within the same hotel.  The restaurant was named after the RMS "Titanic", precisely because it was located above the Atlantic within the hotel.  The menu served a simplified menu compared to White's other restaurants due to the number of covers that the restaurant could hold.  The Titanic was poorly received by critics, with criticism directed at both the décor and the food.

Piccadilly Theatre: The Piccadilly Theatre is a West End theatre located at 16 Denman Street, behind Piccadilly Circus and adjacent to the Regent Palace Hotel, in the City of Westminster, England.

Palace Hotel, Helsinki: The Palace Hotel is an historic modernist hotel in Helsinki, opened in 1952, the year of the Helsinki Olympic Games.  The building was designed by architects Viljo Revell and Keijo Petäjä, and was constructed during 1949–1952.  In addition to the Palace Hotel and related restaurants, the building hosted also the main offices of the Confederation of Finnish Industry and Employers.  The interiors of the building were furnished by various renowned Finnish interior designers, such as Olli Borg, Antti Nurmesniemi and Olavi Hänninen.

Palace Hotel, San Francisco: The Palace Hotel is a landmark historic hotel in San Francisco, California, located at the SW corner of Market and New Montgomery streets.  The hotel is also referred to as the "New" Palace Hotel to distinguish it from the original 1875 Palace Hotel, which had been demolished after being gutted by the fire caused by the 1906 San Francisco earthquake.

Vinoy Park: Vinoy Park is an 11.6 acre park located on the downtown waterfront of St. Petersburg, Florida.  Vinoy Park was named after the Vinoy Park Hotel, which was originally called the Vinoy Park when constructed in 1925 and sits adjacent to the park.  Vinoy Park is operated by St. Petersburg's Parks and Recreation group.  The downtown waterfront park hosts yearly events including St. Petersburg's Ribfest, Tampa Bay's Blues Festival, Christmas displays, and various other events such as art festivals, concerts, and triathlons.

Regent Palace Hotel: The Regent Palace Hotel was a large hotel in central London close to Piccadilly Circus between 1915 and 2006.

Palace Hotel Residential Tower: The Palace Hotel Residential Tower is a proposed residential skyscraper at the corner of Jessie & Annie Streets in the South of Market district of San Francisco, California.  If constructed as proposed, at 204 m and 60 stories, will be the tallest residential building in the city, and the tallest South of Market.  The tower would replace an annex of the Palace Hotel.

Supporting paragraphs: Piccadilly Theatre Piccadilly Circus
Answer: 1819