I was in London visiting back in 2013. The IWM had just closed for renovations.
So, determined to find WWII history, I visited RAF Hendon. That one visit removed several airframes (WWI & WWII) from my bucket list.
As for your comment on the Holocaust, #1 reason why I support Israel today.
On all the other atrocities, I am glad we outnumber the sick and twisted.