Starling nest

I'd be interested to see how your starling boxes are located (outside pic if poss!), and also more details on the boxes themselves (internal dimensions, hole size) if you don't mind. I've got loads of starlings around, and even had them nesting in our eaves over the years, but not managed (yet) to get one into the two boxes I put up this year. Lots of inspections through the hole, but none have actually gone completely inside.