adjective

(of a building or object) in a state of disrepair or ruin as a result of age or neglect.

old, dilapidated buildings

run down,tumbledown,ramshackle,broken-down,in disrepair,shabby,battered,rickety,shaky,unsound,crumbling,in ruins,ruined,decayed,decaying,deteriorating,deteriorated,decrepit,worn out,neglected,uncared-for,untended,unmaintained,badly maintained,the worse for wear,falling to pieces,falling apart,gone to rack and ruin,gone to seed,shambly,slummy,shacky,rumpty