From brewery visits to backstage peeks into theatres, secret insider tours are becoming, well, less of a well-kept secret.

Led by trained guides, these tours take visitors into limited-access places, such as the breeding facility in an aquarium or into the bowels of a brewery where beer is made.

For many of these organisations, such back-of-house tours are an opportunity to share their processes with visitors.

At Esplanade - Theatres on the Bay, visitors can get a better understanding of how shows are staged after accessing places such as the orchestra pit.

Ms Loy Wei Kiin, The Esplanade Co's head of customer experience, says: "We know that beyond coming to the centre to watch performances, there are also many who want to find out more about what goes on behind-the-scenes at a performing arts centre."

At the S.E.A. Aquarium, the VIP Tour that enables participants to "understand the workings of the aquarium and hard work put in by the team of aquarists in caring for more than 100,000 marine animals", says a Resorts World Sentosa spokesman.

Newater tour

To the layman, the Newater factory in Bedok that is within the Newater Visitor Centre may look like a mass of pipes, but it does a crucial job of providing Singapore's water supply.

It is one of five plants on the island that produce 40 per cent of the country's water needs.

To learn more about the process of water purification (right), sign up for a free tour at this factory. It takes slightly more than an hour.

A glass-walled viewing gallery allows you to see the equipment carrying out the three main processes of water treatment - microfiltration, reverse osmosis and ultraviolet disinfection.

Nature-related tours

Zoos and aquariums are traditionally great places for the family to learn about nature.

For a fee, you can sign up for a behind-the-scenes tour that lets you step into the shoes of zookeepers and aquarists.

The Singapore Zoo and River Safari offers eight themed tours. One of them is the African Hooves And Horns tour, a one hour-and-45 minute guided walk around the Wild Africa zone.

One of the perks of the tour is that visitors will get to feed the giraffes and white rhinoceros before other visitors. They will then be led to the restricted-access rhino dens, where they can stroke the white rhinos.

At the S.E.A. Aquarium in Resorts World Sentosa, a three-hour VIP Tour takes you to back-of-house areas such as the holding facility for sea jellies.

One of the aquarium's biggest draws is its Open Ocean Habitat exhibit that is home to 40,000 marine animals, including manta rays. During the tour, visitors go to the top of the tank and watch aquarists feed the creatures.

Another tour with behind-the- scenes experiences is Ocean Dreams, where you can camp at the aquarium in front of the Open Ocean Habitat.

If you are interested in a tour about flora and not fauna, sign up for the Singapore Botanic Gardens' Race Against Time - Science Behind A Botanic Garden tour.

In this free hour-long tour, visitors step inside the herbarium, which is typically closed to the public. The herbarium collects thousands of specimens from the region and their reference materials, some of which date to 1790.

The guide will share stories behind some plants, too, such as the Galeola nudifolia, an unusual orchid that grows inside and around rotting tree trunks.

Backstage tours

Where do performers go between scene changes? Are green rooms really green? Where are costumes stored? These questions and more are answered on backstage tours held by three arts venues in Singapore.

The first is the Esplanade Tour, which is a walk through the 15-year-old venue's theatre and concert hall, as well as backstage facilities.

Running since 2002, the tour grants access to areas usually limited to professional performers and staff. For example, visitors can get up close with the pipe organ located above the stage in the concert hall, a massive instrument made up of 4,740 pipes and 61 stops.

The 1 1/2- to two-hour tour also goes into the dressing room areas and lets visitors see the Esplanade's version of the Green Room, which is the general term used to describe the waiting room for performers before they take the stage.

Like many other venues, the walls of the Green Room here are not all painted green.

Over the years, it has hosted the likes of English soul singer Joss Stone and American singer Jason Mraz.

Also pulling back the curtains is The Star Performing Arts Centre in Buona Vista, which has been offering a 90-minute front of house and backstage tour since 2015.

Visitors can explore the venue's four key spaces, including The Star Theatre and The Star Gallery, as well as its back-of-house facilities such as the broadcast control facilities room and dressing rooms.

Fans of A-mei, Backstreet Boys or Il Divo can snap photos of the Stardom Wall of Fame backstage that is lined with the names of artists who have performed at the venue.

If the stage of the 5,000-seat Star Theatre is not in use, you can also step onto it and enjoy your five minutes of imaginary fame and applause.

At the Singapore Dance Theatre's (SDT) home in Bugis+, participants on its behind-the-scenes tour can go one step further and catch the dancers in rehearsals in four studios.

Besides observing what is going on in there, you visit the wardrobe room, where more than 1,000 costumes are stored, and the shoe room, where the pointe shoes, ballet slippers and boots of the dancers are kept.

Conducting the hour-long tour is Ms Amanda Lim, the company's education and outreach executive, who will provide dance trivia such as the differences between the tutus used in a neoclassical ballet and a contemporary one.

The tours were introduced because "there is a lack of familiarity with how dancers get ready to perform and what happens before the curtain goes up", says Janek Schergen, the company's artistic director.

"This is a way to give a better impression of what goes into making a performance," he says.

Food and drink tours

Want to try an ice-cold mug of Tiger beer direct from the brewery? Going on the behind-the-scenes tour at Asia Pacific Breweries' Tuas factory is a great way to try a super fresh pint right where it has been made.

On the hour-long Tiger Brewery Tour, you learn about the process of brewing beer as well as the rich history behind this iconic 85-year-old local brand.

For example, you can observe thousands of beer cans moving through conveyor belts from machine to machine and look at 44,000-litre mash tuns, where crushed malt is brewed with warm water.

The tour ends at the Tiger Tavern bar, where you get to sample a range of beers brewed at Asia Pacific Breweries' factory free-flow for 45 minutes. The regional brewer and distributor also makes beers such as Heineken and Anchor Beer.

The Tiger Brewery Tour is one of the behind-the-scenes food factory tours in Singapore that allows participants to learn about the history behind local food brands as well as sample their produce.

Guan Hin Coffee, a 37-year-old local coffee powder manufacturer, also conducts tours at its Bedok factory. The tours are led by second-generation owner Chew Theng Kuan, 68, and his daughter Zhou Zhi Juan, 27.

Visitors will witness the different stages of producing a cup of authentic Nanyang coffee, from raw coffee beans being roasted in four giant roasters to watching it being processed in a grinder.

Mr Chew will also demonstrate how coffee beans were traditionally roasted in the 1970s using a small manual hand roaster that belonged to his father.

After that, visitors can fill up their own sachets of coffee powder to take home and learn to hand-brew the perfect cuppa using a traditional coffee sock.

Mr Chew, who took over his father's business in 2011, has been running these tours since 2013 to expose younger people to the heritage and processes of local coffee. He says: "The younger generation doesn't know what makes our traditional black kopi so different from the Starbucks they drink."

The factory still makes use of some equipment Mr Chew's father designed, such as a make-shift pulley system.

Despite the lack of modern machinery, the factory churns out 2,400kg of roasted beans a day, which are then exported to overseas markets such as China and Japan.

Finally, there is My Genie Gourmet's tour, held at the kueh and curry puff maker's factory in Hougang. The 20-year-old company distributes its products to its four Genie Foods outlets and other wholesalers.

Watch how local delights such as curry puffs and soon kueh - a traditional Chinese dumpling stuffed with turnip - are made by hand. You can also buy some of the products to take home. A curry puff costs $1.30 and a box of five soon kueh costs $3.50.