The European tree frog is the only species (or according to some several species) of tree frogs that live in Hungary.
European tree frog (Hyla arborea), nature reserve at Csipak-semlyék, Hungary.
Growing up in Hungary I have always been fascinated by these little tree frogs because they were so different from all the other species of frogs that I have ever seen. Unfortunately for me as a child they do not make very good pets as they like to jump a lot and just bang themselves to death if someone tries to keep them locked up in any small enclosure.
Unfortunately for the frogs people have all sorts of semi-superstitious beliefs about them, such as that they can predict the weather and tell you when it is going to rain by climbing upwards.
European tree frogs are not particularly threatened in the wild at this time because their range is very large and their population is numerous but the long term trend is a population decrease.
See also: American Green Tree Frog.
Further Readings:
Habitat fragmentation causes bottlenecks and inbreeding in the European tree frog (Hyla arborea).
European tree frog on Wikipedia.