indestructible
adjective
ˌɪndɪˈstrʌktəbl 
ˌɪndɪˈstrʌktəbl that is very strong and cannot easily be destroyed
plastic containers that are virtually indestructiblean indestructible bond of friendship
Definition of indestructible adjective from the Oxford Advanced Learner's Dictionary
ˌɪndɪˈstrʌktəbl ˌɪndɪˈstrʌktəbl 