The historic centre of the city, Indre By or the Inner City, features many of Copenhagen's most popular monuments and attractions. The area known as Frederiksstaden, developed by Frederik V in the second half of the 18th century in the Rococo style, has the four mansions of Amalienborg, the royal residence, and the wide-domed Marble Church at its centre. Directly across the water from Amalienborg, the 21st-century Copenhagen Opera House stands on the island of Holmen. To the south of Frederiksstaden, the Nyhavn canal is lined with colourful houses from the 17th and 18th centuries, many now with lively restaurants and bars. The canal runs from the harbour front to the spacious square of Kongens Nytorv which was laid out by Christian V in 1670. Important buildings include Charlottenborg Palace, famous for its art exhibitions, the Thott Palace (now the French embassy), the Royal Danish Theatre and the Hotel D'Angleterre, dated to 1755. Other landmarks in Indre By include the parliament building of Christiansborg, the City Hall and Rundetårn, originally an observatory. There are also several museums in the area including Thorvaldsen Museum dedicated to the 18th-century sculptor Bertel Thorvaldsen. Closed to traffic since 1964, Strøget, one of the world's oldest and longest pedestrian streets, runs the  from Rådhuspladsen to Kongens Nytorv. With its speciality shops, cafés, restaurants, and buskers, it is always full of life and includes the old squares of Gammel Torv and Amagertorv, each with a fountain. Rosenborg Castle on Øster Voldgade was built by Christian IV in 1606 as a summer residence in the Renaissance style. It houses the Danish crown jewels and crown regalia, the coronation throne and tapestries illustrating Christian V's victories in the Scanian War.