The 84-year-old monarch, who was last in the Big Apple in 1976 and at the UN in 1957, wore a two piece white ensemble with blue and beige print and a matching silk hat as she arrived with husband Prince Philip for the one-day visit, which followed a nine-day stay in Canada.

She was at the UN as queen of 16 states and head of the British Commonwealth.

From there she went to Ground Zero where she was met by an honor guard and local officials including Mayor Michael Bloomberg. Following the ceremony she met with relatives of victims.

Paula Berry, who lost her husband on 9/11, told NY1 television the queen "was conveying a message to us."

Berry said she'd repeatedly told her young children that 9/11 had been "a world event and this really reinforces that message."

After opening Manhattan's British Memorial Garden, dedicated to the 67 British victims of 9/11, Elizabeth II was flying home.

New York is accustomed to celebrities and heads of state, but the queen's visit provided welcome distraction from a record heatwave.

The National Weather Service measured 103 degrees Fahrenheit (39.45 Celsius) in Central Park in mid-Manhattan, easily breaking the 101 degrees record set for July 6 back in 1999. Heat warnings were posted throughout the region.