As the Sept. 30 closure of Thailand's oldest zoo draws closer, the future of a World War II air-raid shelter, the only historical spot inside the zoo, remains unclear.

After having been open to the public for eight decades, Dusit Zoo announced in early August that the zoo at the current location in central Bangkok will be no more.

Visitors have since flocked to the soon-to-be defunct zoo to refresh their old memories from their childhood days, or simply to enjoy being around animals.

But some Thais have also wondered what fate awaits the old underground shelter, which was built by the Thai government in the years following the 1941 Japanese invasion to protect Bangkok citizens from Allied bombing raids.

Thailand was a neutral country when Japan invaded it on Dec. 8, 1941, just after attacking the U.S. Pacific Fleet at Pearl Harbor. It forced Thailand to allow passage for its troops to fight to capture British-held Malaya and Burma.

A number of air-raid shelters were subsequently built across Bangkok, including at Dusit Zoo, which was once a public park.

After the war ended, the underground shelter -- a rectangular room 10 meters long, 4 meters wide and 2 meters high -- was turned into an exhibition at the zoo.

In the corner of the damp, dimly lit shelter sit statues of a huddled-up family, including one of a woman cradling a baby in her lap.

Natthapong Pingate, 46, who was visiting the zoo recently with his aging mother, understands why the zoo's planned relocation to a far bigger place outside Bangkok will be good for its animals, but cannot help but feel a bit of sadness over the zoo's closure.

"When my mother was young, she witnessed the bombing, which wrought damage not only across central Bangkok, but also in the outskirts of the capital. To us, the air-raid shelter is a reminder of the war," Natthapong said.

Many air-raid shelters in Bangkok no longer exist, including a large one that was once in front of Hua Lamphong Railway Station, the capital's main railway station. That shelter has been replaced by a fountain and elephant monument.

Those that remain are scattered at a few places, such as Parusakawan Palace, which now hosts the headquarters of National Intelligence Agency, Suan Sunandha Rajabhat University, a public university near the zoo, and Asiatique The Riverfront, a large shopping mall by the Chao Phraya River.

The government's Zoological Park Organization says the zoo's closure, delayed by one month to accommodate an influx of visitors, will not be further postponed.

The zoo will be relocated to a site in Pathum Thani Province north of Bangkok three times the size of the current site. However, construction of the new zoo has not yet begun; it is expected to begin next year or later, with the opening planned within the next three years.

Its more than 1,000 animals are being temporarily transferred to six public zoos in different provinces.

Chonlada Khumlap, a 20-year-old university student, hopes that the air-raid shelter will remain open to the public, even after the zoo closes, to help Thais learn about history.

"If the air-raid shelter is demolished or access to it is prohibited, I think it would be bad," said Chonlada, during her first, and possibly her last, visit to the zoo.

Chonlada said she was taught at school about World War II -- such as foreign invasion of her country, Thailand being part of the war and the war's effects on Thai people -- but had never visited a real wartime relic before.

"Being inside the narrow and pitch-dark shelter, I felt sad. It must have been so scary to be there during the war."

As to the fate of the air-raid shelter, Pitak Unson, director of Dusit Zoo, said it is up to the Crown Property Bureau, the zoo's landlord. No official announcement has been made on the future plan for the overall property yet.

King Chulalongkorn, who laid the foundation of modern Thailand during his 1868-1910 reign, established the Royal Private Garden and introduced a herd of axis deer from Java Island in what is now Indonesia and other wild animals into the garden.

Dusit became the first public zoo in Thailand in 1938 following a royal permission given by King Ananda Mahidol, an uncle of the current king.

Over the years, the zoo grew to become one of the most popular tourist attractions in Thailand, drawing more than 2 million visitors a year and generating 150 million baht (around $4.6 million) in revenue for the country.