Heard about this the other day, or rather read about it.
In Google Maps, you can zoom in manually on some areas further than is possible with the on-screen control.
You've got to press the "Link to this page" link, and then modify the URL parameter "z" to a higher value.
I tried this just now with an address in Den Haag, The Netherlands that I was looking up, and to my surprise it worked.
Here's a plein in the center of Den Haag zoomed in to zoom value 22.
Spuiplein 150, 2511 DG Den Haag - Google Maps