Castle Square is a historic square in front of the Royal Castle – the former official residence of Polish monarchs – located in Warsaw, Poland. It is a popular meeting place for tourists and locals. The square, of somewhat triangular shape, features the landmark Sigismund's Column to the south-west, and is surrounded by historic townhouses. It marks the beginni…Castle Square is a historic square in front of the Royal Castle – the former official residence of Polish monarchs – located in Warsaw, Poland. It is a popular meeting place for tourists and locals. The square, of somewhat triangular shape, features the landmark Sigismund's Column to the south-west, and is surrounded by historic townhouses. It marks the beginning of the bustling Royal Route extending to the south.