Photographs selected by Quentin Nardi

Started by the American Tortoise Rescue, the first World Turtle Day was observed on May 23, 2000. For more than 30 years, the organization has helped rehome turtles and tortoises, animals that inhabit every continent—except Antarctica—with the United States boasting the greatest number of turtle species.

From small spotted turtles that practically fit in your hand to the giant tortoises of the Galápagos Islands, turtles have been fascinating us for eons. The green sea turtle, for example, has been around for 100 million years and plays an important part in maintaining our oceans. That’s just one reason to celebrate turtles this World Turtle Day.

A newborn olive ridley sea turtle
A newborn olive ridley sea turtle emerges from its egg. Buried by a parent more than a month ago, the turtle will find its way to the sea.

  Saurabh Chakraborty, India, 2018
Two turtles keep it cozy
Two turtles keep it cozy, seemingly sleeping, on a log partly submerged in peaceful waters. Gina Gomez, New York, 2013
The Pacific
Sunlight pierces the surface of the sea, offering a glimpse at life in the beautiful waters of the Pacific. Christopher Doherty, Hawaii, 2013

Olive ridley sea turtles return to the ocean
After burying their eggs in the sand, olive ridley sea turtles return to the ocean, leaving behind their eggs, which normally hatch in 40 and 60 days. Kallol Mukherjee, India, 2023
Early Morning Sunlight
A green sea turtle swims nearby a local reef in Deerfield Beach as rays of early morning sun light his way. Max Blakesberg, Florida, 2022
A smaller turtle climbs on the back of a larger one
A smaller turtle climbs on the back of a larger one to get a better view of things at Allegany State Park. Justine Smith, New York, 2021

Two sea turtles exchange a kiss
Two sea turtles exchange a kiss in an apparent public display of affection. Giacomo d’Orlando, Thailand, 2022
Galápagos giant tortoises
Thanks to successful conservation efforts, Galápagos giant tortoises still roam the Galápagos archipelago and are easy for visitors to find. Tom Shlesinger, Ecuador, 2021
A green sea turtle
A green sea turtle, thought to be one of the few turtle species that nest on the Galápagos islands, rests on colorful volcanic rock. Tom Shlesinger, Ecuador, 2021

Turtle & Fish
Remora fish are known to remove parasites found on turtles and clean them by ingesting scraps of food, feces and plankton on their host. Remoras benefit by using the larger creatures as transport and protection. Thien Nguyen Ngoc, Malaysia, 2022
Two leatherback sea turtle hatchlings
Two leatherback sea turtle hatchlings team up for their journey to the ocean. Ben Hicks, Florida, 2015
A turtle comes up for air
A turtle comes up for air. Although they can hold their breath for long periods of time, they cannot breathe underwater. Tom Shlesinger, Florida, 2021
Tortoise
The Tanganyika Wildlife Park is home to this tortoise and about 400 other animals. David Kiger, Kansas, 2019
Buffet of vegetation.
Green sea turtles enjoy the waters of the Galápagos and its buffet of vegetation. Terry Goss, Ecuador, 2012
6 Turtles
Six turtles bask on a fallen log in Dhaka as lake waters mirror their images. Sultan Mohammed Asif Hossain, Bangladesh, 2022

Get the latest Science stories in your inbox.

Tracy Scott Forson is a senior editor at Smithsonian magazine.