We were barely 10 steps inside the dimly-lit stone tunnel that houses the Ten Courts of Hell when my friend jumped back and grabbed my arm. She had approached a mock replica of the "Mirror of Retribution" – where evildoers see their life replayed before they face punishment for their sins – and a demonic apparition had appeared out of nowhere through the looking glass. She calmed down from the shock. "He does have a nice collarbone," she noticed.

Any walk through this grim Hadean fairytale is laced with a mixture of curiosity, disgust and a little humour. The Ten Courts of Hell can be found at Haw Par Villa, a Chinese mythology theme park in Singapore with more than 1,000 statues and dioramas glorifying Buddhist, Taoist and Confucian folklore. Built in 1937 by brothers Aw Boon Haw and Aw Boon Par – famous for selling the popular medicinal paste Tiger Balm – older locals look back fondly at a place where parents would bring children for an education in morality, complete with bloody visual aids.

Thousands used to throng the park, and it once stood shoulder-to-shoulder with attractions like Singapore Zoo and Jurong Bird Park. "Every Singaporean over the age of 35 probably has a picture of themselves at Haw Par," said Desmond Sim, a local playwright. Those pictures would probably include the following statues, each made from plastered cement paste and wire mesh: a human head on the body of a crab, a frog in a baseball cap riding an ostrich, and a grandmother suckling at the breast of another woman.

But the highlight of this bizarre park are the Ten Courts. A tableau of severe disciplines are shown in painstaking detail, along with a placard stating the sin that warranted it. Tax dodgers are pounded by a stone mallet, spikes driven into a skeletal chest cavity like a bloodthirsty pestle in mortar. Spot the tiny tongue as it is pulled out of a screaming man, watch the demon flinging a young girl into a hill of knives. Ungratefulness results in a blunt metal rod cutting a very large, fleshly heart out of a woman. Perhaps the most gruesome depiction is an executioner pulling tiny intestines out from a man tied to a pole. The colons were visible and brown. The crime? Cheating during exams.

However, Haw Par Villa is facing an afterlife of its own. Hardly anyone goes there anymore, and closed sections of the park point to an uncertain future. For some it's a refreshing antidote to the mall-culture, but it looks like mall culture is winning out over a day out in hell. RemSG, the blogger behind the Remember Singapore website, believes new investment is needed. "Its future, in my opinion, is certainly pessimistic," he said.

During our visit, a father could be heard telling his bespectacled daughter to "do your homework, and you can spend more time with the iPad". Unless, of course, you want to be crushed by a boulder.

Haw Par Villa is next to the Haw Par Villa MRT station, and is open daily from 9am to 7pm. Entry is free.

Suoi Tien Cultural Theme Park, Vietnam

A winning combination of water slides and Buddhism, this splash park in Vietnam is a fitting homage to the nation's most popular religion. Legendary animals such as dragons, unicorns, tortoises and phoenix adorn the park, while staff dress up as the mischief-making monkey character from Buddhist mythology to entertain visitors. The vast attraction features swimming pools, boat rides and, for the real thrill seekers, a pool with over a thousand hungry crocodiles that visitors can feed with raw meat.

Entry: £1.50 per adult (children pay half the adult price), plus additional fees for individual rides. More information: vietnamonline.com

JeJu Love Land, South Korea

Unsurprisingly, Love Land is the "only sexual theme park in Korea". Opened in 2004, the attraction showcases works of art created by 20 graduates from Hongik University in Seoul - as well as regular visiting artists - and is a place "where sexually oriented art and eroticism meet". The park is littered with sculptures demonstrating the various sexual positions, as well as plenty of phallic statues and stone labia to cast your eyes over. There are also fun interactive exhibits, such as the invitingly named "masturbation cycle". Sticking to the obvious theme, the park's two mascots consist of Bulkkeuni, a phallus with a red nose and Ssaekkeuni, a vagina that wears a floppy pink hat.

jejuloveland.com

Republic of the Children, Argentina

Based in the city of La Plata, the Republic of the Children is a mini town where the children rule. It features all the institutions you would hope a functioning society to have; parliament, courthouse, church, even a municipal bank. The park was opened in 1951 and was built by the Eva Perón Foundation, a charity set up by the Argentine political leader – and hopes to teach children how to be good citizens in a democratic country. It's either the most incredible, or the most completely dull idea for a theme park around. Leave it to the kids decide.

Entry: $15 (age seven and above), children under seven free, fundacionvalorar.org.ar