What is this?

[homeowner0]

Does anyone know what this is and can it be removed? Thanks

 

[JohnD]

It looks like a balanced flue to me, but you provide no dimensions, do not say where it is, and do not show what's around it.

Perhaps there used to be a gas heater or boiler nearby. Or an extractor fan.

 

[Alec_t]

+1 for balanced flue for a boiler.

 

[homeowner0]

Thank you for your replies and sorry for the lack of information, the dimensions are approx L45cm x W15cm x H35cm.
It's located no where near my boiler but on the external bathroom wall. Extractor fan is higher up.
Also adding that my neighbours are using it as an ashtray! Ideally I would like it completely removed

 

[Old Salt]

Nice neighbours

 

[Alec_t]

It's located no where near my boiler but on the external bathroom wall.

There may have been a boiler there previously.

 

[^woody^]

It's an old boiler flue. If there is no boiler on the end of it, it's redundant and can be removed and the wall made good.