With 30 hectares (74 acres) of pine forest, it could be Beirut's answer to New York's Central Park, but for 20 years the capital's largest green space has been de facto off-limits to Lebanese.

It's a galling situation for residents of the city's concrete jungle, where activists have spent years campaigning for Horsh Beirut to be reopened to the public.

They have faced reluctance from the local municipality, which says the park that accounts for two-thirds of Beirut's green space is not properly equipped to receive crowds of visitors.

Home to around half of Lebanon's population of roughly four million, Beirut and its suburbs are a sprawl of traffic-clogged streets crammed with construction that has eaten into the city's parks and gardens.

For decades, access to Horsh Beirut has been carefully restricted: would-be visitors require permits from the city's governor, and applications are only possible for those over the age of 30, or children under 10 accompanied by their parents.

"I had to sign a document pledging that I would keep the park clean and tidy and that my doctor had recommended I exercise," said Michel, a Lebanese resident of Beirut.

"They are supposed to get back to me in 10 days."

The onerous process renders the park, which is also known as Horsh al-Snobar (Pine Forest), effectively off-limits to the average Lebanese, and has enraged local civil campaigners.

"It's like preventing New Yorkers from accessing Central Park," said Joanna Hammour, of the Nahnoo (We) NGO, which is fighting to reopen the forest and has threatened to sue the municipality over the restrictions.

"The closure of Horsh Beirut is illegal. It's a public space," Hammour, 32, said.

- 'It's my right' -

To make matters worse, activists say the restrictions seem to be waived for Westerners.

"We discovered that many foreigners have entered the forest without permits," Hammour said.

"I entered without anyone stopping me, but the guards prevented a Lebanese friend from meeting me inside," recounted shocked American researcher Lynn Staeheli.

Beirut's once plentiful green spaces have largely fallen victim to the rampant development that followed the end of Lebanon's 1975-1990 civil war.

According to a study by the Lebanese architecture firm Habib Debs, there is just 0.65 square metres (seven square feet) of public garden for every Beirut resident, a far cry from the 10 square metres recommended by the World Health Organization.

The percentage of non-built-up land in the city has fallen from 40 percent in 1967 to just 10 percent in 2000, the study said.

Outside the walls of Horsh Beirut, joggers pound the sidewalks while the park inside is virtually empty.

"I don't have the right to go and read or engage in any activity in Horsh Beirut because of my age, even though it's my right," said 25-year-old Ziad Lyan.

- 'Treat us like children' -

The Beirut municipality says the issue is one of resources and the forest is simply not equipped to receive a large number of visitors.

"With 300,000 square metres of land, it's Beirut's lung," said municipal chief Bilal Hamad.

"We can't ensure security or cleanliness with forces from the municipal police," he told AFP, noting that the park lacks toilets or bike lanes.

"Imagine if someone started a fire."

Hamad said tender bids would be launched this summer to contract a private company to provide the park's "management and security", with an expected opening some time in 2016.

But that does nothing to reassure civil activists.

"There is no reason to appeal to private companies," said Nahnoo president Mohammed Ayoub.

He said the municipality has a budget surplus of hundreds of millions of dollars, giving it the means to provide guards and keep the park clean.

"They treat us like children who are denied a toy in case they break it," grumbled Lyan.

Hamad said the municipality has plans to build a 10,000 square metre botanical garden in the park in cooperation with the municipality of Geneva, along with an amphitheatre and an Olympic stadium with underground parking on the site of an old training area.

"Not a single tree will be cut down," he promised, in the face of angry accusations from activists that such development would be "a crime".

They say the forest, which lies on the line that divided Beirut during the civil war and was devastated during Israel's 1982 invasion, should serve as a unifying space for the city's residents.

"Horsh Beirut should reopen as a symbol of unity, peace and reconciliation between residents," Hammour said.