Guide is a type of Structure. Structure is related to Mountain. Mountain is related to Tunnel. 
Republic is related to Party. Party is related to Crowded. Crowded is related to City. 
Guide --IsA--> Structure <--RelatedTo--> Mountain <--RelatedTo--> Tunnel 
Republic <--RelatedTo--> Party <--RelatedTo--> Crowded <--RelatedTo--> City 