(CNN) -- What makes a zoo or aquarium outstanding?
Stellar recreations of natural habitats?
Plenty of sugary refreshments for the kids?
The new Travelers' Choice awards for Zoos and Aquariums around the world issued by travel website TripAdvisor is light on captive-collection specifics but high on opinion.
Naming 275 zoos and aquariums in total, the awards call the Henry Doorly Zoo in Omaha, Nebraska, the world's best.
The San Diego Zoo in California comes in second place.
Monterey, California's Monterey Bay Aquarium tops the list of world aquariums.
"The U.S. leads the tally of world lists of zoos and aquariums, with nine of the top 25 zoos (and) 10 of the top 25 world aquariums," said the U.S.-based website in a statement accompanying the announcement of the awards.
The site says its awards are based on "millions" of reviews from its users.
"Award winners were determined using an algorithm that took into account the quantity and quality of reviews for zoos and aquariums worldwide, gathered over a 12-month period," said the website.
Renamed and reorganized in the 1960s by the Omaha Zoological Society, the Henry Doorly Zoo has roots dating to the 1880s when, as Riverview Park, it contained about 120 animals, including two bison on loan from "Buffalo Bill" Cody.
Today, the zoo has "thousands of animals from around the globe, 130 acres of exhibits and gardens including seven acres of indoor exhibits," according to the zoo.
The highest-ranking non-U.S. zoos in the survey are Spain's Loro Parque (#3 overall) and Singapore Zoo (#5 overall).
The highest-ranking non-U.S. aquariums are Portugal's Oceanario de Lisboa (#2 overall) and Greece's Aquaworld Aquarium (#6 overall).
The complete list of TripAdvisor Travelers' Choice awards for zoos is online at TripAdvisor.com. The complete list of aquariums is also at TripAdvisor.com.
World's top 10 zoos according to TripAdvisor
1. Henry Doorly Zoo (Omaha, Nebraska)
2. San Diego Zoo (San Diego)
3. Loro Parque (Puerto de la Cruz, Spain)
4. St. Louis Zoo (St. Louis)
5. Singapore Zoo (Singapore)
6. Chester Zoo (Chester, UK)
7. Prague Zoo (Prague)
8. Tiergarten Schoenbrunn—Zoo Vienna (Vienna)
9. Bioparc Valencia (Valencia, Spain)
10. Gramado Zoo (Gramado, Brazil)
World's top 10 aquariums according to TripAdvisor
1. Monterey Bay Aquarium (Monterey, California)
2. Oceanario de Lisboa (Lisbon, Portugal)
3. Georgia Aquarium (Atlanta)
4. Tennessee Aquarium (Chattanooga, Tennessee)
5. Ripley's Aquarium of the Smokies (Gatlinburg, Tennessee)
6. Aquaworld Aquarium (Hersonissos, Greece)
7. Dallas World Aquarium (Dallas)
8. Vancouver Aquarium (Vancouver, British Columbia)
9. Mundomar (Benidorm, Spain)
10. Two Oceans Aquarium (Cape Town, South Africa)