Michael Clarke wrote:

Taking into account that and the complexity of airspace
in Europe, you might want to consider the merits of
flying at various clubs in Europe using club machines.
Almost all of these are members' clubs and welcome
guests.

Whether you want to bring your own glider or not, you'll have to contact
the clubs anyway. Most glider sites are operated by clubs. They usually
welcome guests, but they all have their rules. You can't just show up
and hire a tow.

Stefan