Plavna in Serbia offers a unique experience to travellers. After your splendid visit to Plavna, you can proceed to an important near-by city of Belgrade. So, ideally any vacation planner would recommend you to visit Belgrade for its bountiful attractions like Dunavska Street & Zmaj Jovina Street, Strand, Danube Park on your trip to Plavna. Also, to reach Plavna, you'll have to take a flight to Belgrade; so its not really a detour. And even if it is, the city is worth paying at least a quick visit. A holiday in Plavna can generally be of 1-2 days.
Yes,it is that simple really! Enjoy your trip! Keep travelling!