Across London, there are endless little-known marvels and surprises waiting to be discovered.

At first glance, many look like no different to common attractions or city features, but a more in-depth look will reveal the secrets that lie within. 

From Trafalgar Square's secret tiny police box to forgotten London Underground stations and even the skinny house in South Kensington.

But there is another London secret in some streets that thousands walk past every day but never give a second look.

The humble 'green huts' have a lot more to offer than at first glance.

While many may not know what the green huts of London are used for, they are a lot more practical than you might think.

News Shopper: The huts were built for shelter to cabbies.The huts were built for shelter to cabbies. (Image: PAUL FARMER)

What are London's green huts used for?

Although often called green huts because of their colour, the huts are actually properly called cabmen's shelters.

As their name suggests, they were created to give shelter to cabbies in the Victorian era, with at least 13 still in use across the capital to this day.

In the late 1800s cabbies weren't lucky enough to be able to shelter in their vehicle, instead, horse-drawn carriages were used, with cabbies sitting on a seat on top, open to all weathers.

According to Living London History, the green huts were created so that during bad weather, cabbies could stay safe and take shelter.

The editor of the Globe Newspaper, George Armstrong, came up with the idea of cabmen's shelters after noticing many drivers holing up in a pub to keep out of the weather.

News Shopper: George Armstrong came up with the idea.George Armstrong came up with the idea. (Image: Mike Quinn)

Using MPs' and philanthropists' help, Armstrong founded the Cabmen's Shelter Fund in 1875 to help build the huts across London.

Although the huts were built for protection from the elements, they also served hot food and drink and are said to fit between ten to 13 drivers inside, with hot drinks sold to the public through hatches.

However, there were some rules cabbies had to stick to: there was no alcohol allowed inside, and no card-playing or gambling.

At their peak, green cabmen's shelters offered welcome respite for cabbies, but many were lost to bombing during the Second World War.

More traffic on the roads as well as vandalism and widening of streets took more green huts out of use.

But the remaining 13 huts are still managed by the Cabmen's Shelter Fund, with many now having Grade II-listed status from Historic England in a bid to protect them.