In my opinion, to Bulgaria. For example, in the resort of Albena (flight to Varna), many services for children and good beaches. If you fly to Bourgas, I can advise the resort Sunny Beach. There are gentle beaches with fine sand.

In Croatia, most beaches are pebble or concrete platforms. In the latter case, the sea will have to descend the steps immediately into the depths. An indisputable plus of Croatia is the stunning nature and a large number of national parks