THIS week, a huge black box "mysteriously" appeared in Southend High Street. 

After the Echo shared the image, Facebook users decided to share their best guesses for what the huge black box is for. 

With hundreds and hundreds of comments, here are some of the best suggestions... 

Darren Jason Murphy said: "New series of The Cube being filmed in Southend?" 

Chris Gill added: "The entrance to Narnia."

Sophie Kingman wrote: "It is where they are hiding the Christmas tree this year."

As Vicky Robertson echoed that suggestion with "it is the stand to the Christmas tree this year." 

Gregory Edwards said: "Aliens?" 

With Chaz Henderson joking with: "The Southend Combat Cube: Arm yourself right before walking down the High Street..."

Dean Stevens added: "Possibly they knife bin?" 

Many jumped to the theme it was Doctor Who related, with Many Jane Cook sharing a David Tennant gif and Tracey Wright adding: "Could be Doctor Who". 

A few comments brought Southend United and its chairman, Ron Martin, into the conversation following this club's appearance in court this week. 

Steve Sexton wrote: "Ron Martin's safe?" 

Paul Lee was hoping "new Southend United's owners" would be unveiled within the black box. 

Despite all the funny and great suggestions, the cube in question will form part of the Southend City Jam event.

Southend City Jam is a street-art festival that is being billed as the “largest in Europe”.

It will return on September 1 to September 3 with huge colourful piece of artwork scattered across the city.

The cube will be used as a collab for artists and will see each side of the huge cube painted by a different artist.

There will be 12 of these placed across the city centre in the coming week.