Air Raid Shelter

The house I grew up in was built in 1932 (I wasn't there then), this shelter is dated 1939 just above the door. 
As kids we used to have much fun, daring to venture inside (very dark), and climbing on top and plucking up courage to jump off. It's over 7ft high so that exercise was great for building strong bones. It's a miracle we didn't all break our ankles. Not sure I'd get away with it these days.