If a person has a single entry Schengen visa, would a visit to these microstates be considered as leaving the Schengen area?
I know that Monaco, San Marino and the Vatican City are de facto Schengen but since they "stop" the clock for counting the 90/180 day rule (according to this question) for the time spent there, I wonder whether they do that Also consider it as an exit from the Schengen area.
Specifically, the question concerns the Vatican that other states may be of interest to OPs with a similar problem.
It would be quite a hassle to get stuck in the Vatican. There is only one hotel (Residenza Paolo VI) with prices between 125 and 320 euros. But it would be a shame to visit Rome and not the Vatican.