How to Make Spiked Ruins

you will need

1xtape
1xknife
1xglue
2xcardboard ruin (i used some from the warhammer 40000 2nd edition box set but you can make your own)
8x toothpicks

use the tape to stick the ruins together like in the picture

place the toothpicks where you want them and where they fit nicely (make sure less than half of the toothpicks pokes out) and glue them in place and use the knife to make holes in the side of the ruin where you can glue toothpicks there

now you`re done (also it is treated as dangerous terrain so bonus!!!!!!)