The divyadesams of Vishnu has a connection comprising River, Vimana and Sthala vruksha. Example God Ranganathaswamy of Srirangam temple has cauvery as river, Vimana is Ranga Vimana and Sthala Vruksha [Tree in the temple] is Vilvam. Likewise for other divyasesams. Ancient Siva temples also has River, Vimana and Sthala Vruksha. Any scriptural references how the river, vimana and sthala vrukshas are rightly associated to the respective temples.