Repeat visitors to Bangkok often return to the memorably delightful Royal Palace, Wat Phra Kaew (Temple of the Emerald Buddha), Wat Arun (Temple of Dawn) and other well-known attractions.

But for something different, from creepy to cute, this heaving city’s sidestreets beckon and in them you’ll some of the most bizarre museums, well, anywhere.

• My lunch date with a cannibal
• The hidden paradise that’s on our doorstep
• Could this city be the foodie capital of the world?

For instance, a building in the vast Siriraj Hospital complex – Thailand’s largest medical facility – houses Congdon Anatomical Museum, a fusty repository of oddities aimed at educating would-be doctors and definitely not for the squeamish.

“The 124 year-old former prison displays gruesome torture contraptions.”

“Somehow it featured in a guidebook, tourists started knocking and we opened to the public,” explains Dr Sanjai Sangvichien, a retired professor and the museum’s founder.

Down a row of human skeletons, I notice a bouquet of fresh flowers at one set of bony feet.

“Oh, that’s my Dad,” reveals the professor. “He was also a professor and made me promise he could keep teaching after he died – so I put his skeleton in the museum.”

Displays include limbs and tumours in formalin – and a glass tank containing stillborn conjoined twins. (The term “Siamese twins”- referring to conjoined twins – comes from Thailand, previously called Siam.)

This hall of horrors fills one level, with other floors occupied by museums devoted to pathology, parasitology (particularly malaria) and forensic science (highlighting Thailand’s most notorious crimes).

Similarly creepy but closer to fashionable Siam Square’s malls is the Human Body Museum, within Chulalongkorn University grounds, where preserved bodies are exposed post-dissection to reveal workings of various organs.

Thai Buddhists combine religious beliefs with elements of ancient animism. An example of the latter is faith in amulets to ward off danger. (Taxi drivers commonly keep amulets on dashboards as anti-crash protection.)

Nowhere is faith in amulets’ power more evident than at Bangkok’s Amulet Market. A daily street market, much patronised by saffron-robed monks, it’s often called a museum because many visitors – Thais and tourists – come merely to browse amid medallions, frequently depicting esteemed monks, priced between 200 baht ($A6.66) to 100,000 baht ($A3331.60).

What’s more, it’s only a few minutes’ stroll from the National Museum of Royal Barges, where the longest intricately carved vessel is 46m Suphanahong – the monarch’s personal barge with 54 oarsmen. The vessels participate in festival processions along the Chao Phraya River.

But let’s return to the creepy. In a 124 year-old former prison, Bangkok Corrections Museum displays gruesome torture contraptions (including devices for pushing razor-sharp bamboo skewers under nails), with cells portraying execution methods down the ages.

The most ghoulish: a giant rattan ball with internal spears. Convicted murderers were confined inside, with the ball given to elephants to kick around – impaling the killer.

Far less confronting and a marvellous “green lung” near traffic-plugged Victory Monument is garden-settingSuan Pakkad (meaning “cabbage patch”, its former role). A collection of traditional teak houses relocated from elsewhere in Thailand, it was where a now-dead prince lived and remains one of Bangkok’s least-visited palaces.

Exhibits include pottery and other antiquities, archaeologists’ discoveries and, in one building, lacquered walls with depictions in gold of key historical moments.

But Suan Pakkad’s quirkiness derives from its late owner’s love of music. Displays from his personal collection include old Thai records, traditional instruments, trumpets and saxophones. (Current monarch King Bhumibol Adulyadej is a jazz fan and saxophonist.)

In a country where museums include those devoted to seashells, banknotes, postage stamps and kites (and where an air force museum showcases old aircraft while army facilities allows tourists to drive tanks, fire assault rifles and train for jungle warfare), it’s unsurprising that one museum, 80ha Muang Boran (meaning “ancient city”) aims specifically at time-poor tourists.

It replicates Thailand’s main attractions (including the old cities of Sukhothai and Ayutthaya) in miniature. Visitors walk across a scaled-down Thailand in an hour, stopping at a tiny northern Thai village, complete with transplanted residents.

Muang Boran is particularly popular with families. But, with kids in tow, don’t skip Batman Toy Museum, alternatively known as Batcat, where other superheroes also feature among 50,000 items including toys, comic books and costumes.

Outside Bangkok, Thailand’s fascination with off-the-wall museums is also apparent. The most unusual, in the far-northern Golden Triangle city of Chiang Rai, is the government-funded Hall of Opium. Built into a hillside, it shouldn’t be confused with the smaller but similarly worthwhile House of Opium which is nearby.

Hall of Opium dioramas include an opium den. Displays illustrate poppy cultivation and describe opium’s use in bartering with British traders during the 1800s.

The writer was a guest of Air Asia X and Bangkok’s Metropolitan Hotel.