Kakadu National Park, Australia

Kakadu National Park surpasses #8 Bosque del Apache in year-round avian diversity, with over 280 bird species inhabiting its vast floodplains. This Northern Australian sanctuary hosts enormous flocks of magpie geese and the elusive Gouldian finch, the latter sighted by 12% of dedicated birders annually. Spanning nearly 20,000 square kilometers, it offers a richer, more biodiverse landscape than the typical wetland refuge, supporting 30% more species than the average Top 10 destination.