Teignmouth in Devon is commonly pronounced as Tinmuth,the river Teign is the Teen.
Yealmpton also in Devon is Yamtun,the river Yealm is usually pronounced as Yelm rarely as Yam.
Tideford in Cornwall used to be pronounced as Tiddyfurd as it was a fording place on the river Tiddy,in recent times the incomers have taken to calling it Tide Ford and the change has taken root.