The mother and daughter lay out their picnic on the lawn and lie in the hot spring sun as a group of other women jog past them in spaghetti-strapped vests and lycra shorts.

An unusual sight indeed in Iran, where all women are obliged to cover their hair and body contours in public to obey the country's strict Islamic dress code.

But last month the Tehran municipality opened the "Mothers' Paradise" park in the upmarket north of the city to create a male-free zone every day of the week except Friday.

Built on hills and filled with lush evergreens, it was deemed an ideal spot for any park. It is now surrounded by iron sheets up to four metres (13 feet) high to keep out prying eyes.