"Wanderlust has a circulation of more than 30,000 and our top three finish will stand us in good stead for UK travellers considering where they want to go on their next overseas holiday."
Wanderlust said on its website that it was Namibia's sense of drama and accessibility that won it top spot.
"And that mix of drama and accessibility surely accounts, too, for runners-up Costa Rica and New Zealand - destinations where the natural world pulls out all the stops, but creature comforts are never far away," Wanderlust said.
Other mentions of New Zealand in this year's awards were Air New Zealand, which finished third in the Top Airline category, and the TranzAlpine train journey, which took seventh in the Top Rail Journey category.
In other categories, Myanmar/Burma won Top Emerging Destination, Luang Prabang in Laos was named Top City, and Top Airline went to Singapore Airlines.
The Disservice to Travel award went to Ryanair.
The Wanderlust Travel Awards are held annually and are based on travellers' experiences from December 2009 to November 2010.