Thanks everyone.
Yes, the AIC was my first point of reference, and since we are now almost at the end of the transition period, the AIC implies there will some major CTAs in addition to the TMAs which will be Mode S. Finding out if there are, and where they are is less easy.
I also wanted to find the location of any Mode S airspace in Europe, but the Eurocontrol site is no help either, unless I am missing something.