Mohacs Travel Forum

My friend and I were in southern Hungary last Friday and in the evening (it was already getting dark) we headed to the Duna-Drava national park, south of Mohacs. We wanted to find a quiet place at Duna. In fact, it was very quiet in the park everywhere, anyway. Except for one small road. Taking into account there weren't many cars even on bigger roads (motoways), it made us wonder were all those cars were driving to. We looked at the map and found out the small road was leading to the Croatian border. We wanted to drive and see what was happening there, but we weren't allowed to drive the rented car outside Hungary, and besides it was getting late.
So my quiestion is, was it the illegal way to get to Croatia there? Otherwise, why such a secret path (there are bigger and better roads to Croatia)?
The road runs near Kolkod and Erdofu villages to Duna.