How this chalk mine was transformed into an underground city

Lot's of people sheltered underground in WW2, but 15,000 people in South London took things a step further. Get 4 month extra ExpressVPN using my link: https://www.expressvpn.com/lukeosullivan Watch more of this series: https://youtube.com/playlist?list=PLDft76-0Qb7_Ck4BViVd_CjDGJHlwD58T&si=yFsf4gUMjiriXuSc and more https://youtube.com/playlist?list=PLDft76-0Qb78jLOZQqEalSgh1oT8B58iv&si=Zf_MiU8PWUse0HFD https://youtube.com/playlist?list=PLDft76-0Qb78jltTNnVQ-RTmK-u-dxjpp&si=e1n4GXVjLnphpzcM Thanks to Jason and everyone at the Chislehurst Caves! It's a great day out and it's just over 20 minutes on the train from London Bridge. Find out more on their website here. https://chislehurst-caves.co.uk Hi, my name's Luke. I answer questions nobody asked and find things that make me say 'pretty mad, that.' This video is sponsored by ExpressVPN.