Nasrin and Kimia cast aside their mandatory headscarves and quickly unbutton their coats as soon as they pass a gate watched by male guards --the entrance to Tehran's first women-only park called "Mother's Paradise".
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 meters (13 feet) high to keep out prying eyes.
"It is a good place to take in fresh air and finally dress as you want," said 39-year-old Nasrin who lives nearby and comes to the park almost every day. "In an Islamic country this is as good as it gets."
In Iran it is mandatory for women to wear headscarves but the rules do not apply for women in places where it is forbidden for men to enter.
"We need vitamin D"
The 20-hectare (50-acre) park offers aerobics classes in the open air (something of a craze for both sexes in Iran), a cycling track, a sports hall for team games and even archery courses.
Nahid Foadi, 50, has arrived with friends swinging badminton rackets and gym bags.
"We need vitamin D and all these years our health has been neglected. They have to build more such parks everywhere," she said.
Some women said they felt safer in the park, which is run by an all-women staff of cleaners, gardeners and security guards, complaining about harassment and drug dealers in other parks.
The park is looked after by male staff outside its confines and after 8:00 pm, which is the closing time, regarded as too early by many women.
Unlike other women-only venues, such as swimming pools, sports clubs and concert halls, visitors are not required to hand in cell phones and cameras.
Iran's police have been battling the distribution of compromising footage of women shot secretly in such places on cell phones and posted on the Internet or sold on video CDs throughout Iran.
"We think it is better to trust women and that they would avoid taking pictures for their own good," said a security guard who asked not to be named.
Despite its instant popularity, the park has met with some disapproval, with critics arguing that segregation would not be the right answer to social problems including harassment in public places.
"Men need to be educated to act like responsible citizens and respect women," said Sogol Zand, a post-graduate student on gender studies.
The 38-year-old single woman also objected to the park's name -- Mothers' Paradise -- which "could mean you have no identity as a woman except as a mother."
Critics are also concerned about further male-female segregation in the Islamic republic, which frowns on the mingling of unrelated men and women.
Women ride in the back of public buses in Iran. University canteens, corridors and some classes are also segregated.
The strict rules however do not stop young men and women from hanging out in coffee shops and restaurants, or strolling and holding hands in parks.
"There are 1,500 parks in Tehran and hundreds of gyms only for men. It is an undeniable necessity to create a few parks for women who form 50 percent of the population," Qalibaf said.