Palace

grand residence, especially a royal or episcopal residence

A palace is a place with a grand and imposing building that is the official residence of a king or queen, a head of state such as a president, ruler, or leader. Many historical palaces are now museums that show what royal and aristocratic life was like when it was built.

A palace in India, built in a lake

Besides, it can mean a luxurious House or Mansion( like Biltmore Mansion and Hearst Castle) or a large building for entertainment: a large public or private building with an imposing ornate style, used for entertainment or exhibitions and large events.