Image credit: The Other Room

Ever been to an underground bar that requires a secret password or is simply hidden in plain sight? Well, if you have, then you would have been hanging out at a speakeasy.

These incognito watering holes hark back to a forgotten era when it was illegal to sell alcoholic beverages. Of course, the ones here are properly licensed, but they continue to draw those who love exclusivity and want to stay out of the public eye.

Here's a look at five of the coolest speakeasies in Singapore that offer such elusiveness you can drink in peace to your heart’s content.

The Library: Do your homework before coming

The bookshelf conceals The Library’s bar

The Library is hidden from view behind a bookshelf (Credit: The Library)

Unlike its name, The Library is not open to the public, but only to those who possess the secret password. Obviously, in these days of connectivity, you can't expect the password of such a hip place to be kept hidden for long, so the owners came up with a bright idea – to get in, you need to look out for the password posted on a weekly basis on its sister restaurant’s Facebook page.

Right before you enter that secret book chamber, say the password at the door and you'll be presented with a room full of mirrors. You’ll then be led through a door and rewarded with yummy cocktails served in innovative ways, such as a duck swimming in a bathtub.

Address: 49 Keong Saik Road, Singapore 089153

The Secret Mermaid: CBD folks take a dive underground

The interior of The Secret Mermaid bar

The Secret Mermaid bar is literally hidden – there are no windows! (Credit: The Secret Mermaid)

By day, The Secret Mermaid is actually design-your-own salad bar Shinkansen, situated along the underground walkway of Raffles Place MRT Station. After 5pm though, the eatery transforms into a bar specialising in American craft spirits.

The place is small and cosy – perfect for after-office drinks with colleagues. Not sure what to order? Have a go at the tasting flights, which allows you to savour the bartender's special selections and sample three spirits. We guarantee you'll find something you like!

Address: 10 Collyer Quay, B1-08 Ocean Financial Centre, Singapore 049315

By day, The Secret Mermaid is actually design-your-own salad bar Shinkansen, situated along the underground walkway of Raffles Place MRT Station.

The Other Room: Be surprised by your drink

A person squeezing an orange peel into a cocktail glass at The Other Room

The Other Room serves up delicious, innovative cocktails (Credit: The Other Room)

The relative newcomer in town opened its doors in July. Pouring discerning patrons an exceptional selection of more than 150 premium and craft spirits, all are stripped of their original bottles and placed in identical oak casks.

The Other Room offers an educational and sensational tasting trip as each drink is accompanied by a short commentary of how it is inspired, the alcohol level and its ingredients.

Oh, and did we mention its entrance is somewhat concealed behind a black curtain even though it’s located in the lobby of one of Singapore’s well-known hotels?

Address: Singapore Marriott Tang Plaza Hotel, 320 Orchard Road, Singapore 238865

Ah Sam Cold Drink Stall: Come here for local flavour

Sitting on the second floor along a stretch of shophouses in Boat Quay, the place comes with no menu. The specialty here is innovative and bespoke cocktails with familiar flavours of Singapore – expect MILO and soya bean milk in your drinks. At Ah Sam Cold Drink Stall, they are served with sides such as char siew (barbecued pork).

Address: 60A Boat Quay, Singapore 049848

The Horse's Mouth: Cocktail is the new sake

The bar counter at The Horse’s Mouth

Cocktails and ramen make strange bedfellows at The Horse's Mouth (Credit: The Horse’s Mouth)

Hidden inside Uma Uma Ramen, The Horse’s Mouth is a favourite with bar veterans. With its hidden sliding-door entrance, chic decor and Zen interior, The Horse’s Mouth is a gem of a bar. Who says a ramen lover can't pair his dinner with a cocktail instead of the usual sake?

Address: 583 Orchard Road, #B1-39 Forum The Shopping Mall, Singapore 238884

It's time to take a walk on the wild side and experience the hidden drinking spots of Singapore with these Prohibition-era-inspired speakeasy bars.