make less attractive
despoil - damage
To ‘despoil’ something means to make it less appealing, valuable, or important, typically by forcefully stripping things away from it or causing destruction. The term originally meant 'to strip or rob’ and was used in the sense of stealing goods, but it is now used in a more figurative sense to refer to damaging places or things of beauty like the countryside, etc.
Protestors campaigned vigorously against the proposed new road because they said it would despoil the natural beauty of the surrounding countryside.
There are some who believe that human profligacy and greed has led to the despoilment of our environment.
After local youths broke into the cemetery, the police said that a number of gravestones were cracked and tombs were despoiled by graffiti.