There are plenty of WW1 memorials and Cemeteries that show signs of damage as a result of WW2:
The Menin Gate in Ypres
The Australian memorial at Villers-Bretoneux
The Indian Memorial at Le Touret
The 1st Australian Tunneling Coy memorial at Hill 60
A few years ago I was on a very intersting walking tour of the "London Blitz". If my memory serves me right then the statue to Fd Marshall Haig at Whitehall has Blitz damage on it as does the Guards memorial at Horseguards.