Question - Could someone advise me.

[T_Fletch]

Does anyone know if this is anything special like a air raid bunker or just something that will just waste my time. Spotted since younger but thought nothing off it till now since I saw a video of one similar on YouTube? Advise would be appreciated.

 

[Rainey]

Looks like it's part of a drainage system to me, although the concrete does give a particular vibe. The only way to find that out would be to crack it open.

 

[Nickindroy]

Lid doesn't look like it would take much lifting? Get it sorted!