Places We Protect

Guadalupe-Nipomo Dunes


Guadalupe-Nipomo Dunes on the central coast of California
Guadalupe-Nipomo Dunes Guadalupe-Nipomo Dunes on the central coast of California © Matthew Dillon/Creative Commons

Uncover the mysteries of Earth’s longest coastal dune system



The Guadalupe-Nipomo Dunes are the largest intact coastal dune ecosystem on Earth. They curve up and down for 18 miles along the coast south of Pismo Beach. Here, freshwater lagoons and pristine beaches create a variety of habitats for endangered species like snowy plovers and northern elephant seals. The dunes are filled with plants that are specially adapted to this unique environment, including flat-leafed spectacle pod and an endemic type of mint with flowers that look like fireworks.

These dunes offer researchers and visitors dramatic views of the Santa Maria River Estuary and lots to explore, with sandy peaks reaching as high as the Washington Monument. It’s easy to see why Cecil B. DeMille chose this windswept landscape to be the “Egypt” of his film The Ten Commandments. Today, remains of the set—secretly buried by DeMille’s crew in the 1920s—rise from the sand, including the remains of a giant sphinx. 

Visitors will find many ways to explore this magnificent landscape. The dunes contain miles of hiking trails, an art gallery, a native species garden, several campgrounds and public beaches. 



Dogs are only allowed in some areas, so be sure to check with local agencies.


Most outdoor points of interest are open year-round during daylight hours. The Dunes Center is open Thursday through Sunday from 10:00 am - 4:00 pm. Hours may change as needed due to the COVID-19 pandemic.


Wildlife viewing, beach access, ocean views, and exhibits.


15,000 acres (24 square miles). Approximately 6,000 acres, including Rancho Guadalupe Dunes County Park, Oso Flaco Lake Natural Area, and the Guadalupe-Nipomo Dunes Wildlife Refuge are now protected.

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What to see

Plants: Many interesting and rare plants will be in bloom no matter what season you visit. The dunes' unique deposits of sand and sediment are home to several endemic species, including a sub-variety of dune mint. Some of California’s most notable flora also thrive among the dunes, including California poppies and lilacs. The California lilac, known for its breathtaking purple flowers, has long been used by Native Americans as an herbal tea and additive to soaps. 

Animals: The lagoons and sandy peaks of the Guadalupe-Nipomo Dunes offer food and refuge to a wide variety of birds, mammals and reptiles. Many of the species here are endangered, such as the California red-legged frog, golden eagle, northern elephant seal and the American peregrine falcon. During the winter breeding season, visitors can hear northern elephant seals singing with their large, inflatable noses known as “proboscises.” But, be sure to keep your distance because these huge animals are territorial and dangerous when approached. 

Trails: The Guadalupe-Nipomo Dunes host miles of trails and different agencies lead educational walks through the dunes’ varied ecosystems.

Red-legged Frogs Hop to New Habitat Learn more about the red-legged frog and TNC’s international journey to reintroduce this species to its native habitat in Southern California.

Other Preserve Amenities

  • Dunes Center: The Dunes Center is open to visitors and serves as an area welcome center. The Center is home to research archives, an art gallery and historical exhibits, including artifacts from the The Ten Commandments’ lost Hollywood movie set. Visit The Dunes Center website for more information.
  • Oso Flaco Lake Natural Area: Visitors can explore Oso Flaco Lake’s spectacular ecosystems from a mile-long boardwalk suspended above the lagoon.
  • North Beach and Oceano Campgrounds: Pismo State Beach is a 1000-acre park featuring two full-service campgrounds, miles of trails and nature center. Between spring and fall, docent-led walks are offered for groups or individuals focused on native birds, animals, plants, habitats, geology, and cultural history.
  • Guadalupe Native Plant Garden: The Guadalupe Native Plant Garden is a beautiful place for a meditative rest or an in-depth exploration of plants native to the area. For hours, location and directions, visit The Dunes Center website.


Dunes begin as tiny piles of sand and sediment. The Guadalupe-Nipomo Dunes gathered as sand blew inland from the coast and sediment was swept downstream by the Santa Maria River. Today, the tallest dune—called Mussel Rock Dune—measures approximately 500 feet. In 1987, The Nature Conservancy acquired a 567-acre stretch of the landscape to protect the dune’s important ecosystems. Two years later, we bought another 2,550-acre parcel. Today, most of the dunes' ownership has been transferred to the U.S. Fish and Wildlife Service. 

The Lost City of Demille

The Guadalupe-Nipomo dunes show what the Central Coast once looked like before development. But to filmmaker Cecil B. DeMille, they looked a lot like ancient Egypt. DeMille picked this stretch of coast to be the backdrop for the Exodus scenes in his 1923 film The Ten Commandments. His team built a set of replica pyramids, temples and sphinxes, and once filming concluded, they buried these set pieces under the sand. For the next 60 years, the entombed set lay forgotten until a group of fans followed a cryptic clue in DeMille’s autobiography to the set’s remains in 1983. Today, The Dunes Center has pieces of the recovered set on display.

Hope for the Coast With 90 percent of large cities located near coasts, billions of people and billions of dollars of infrastructure are directly at risk from sea-level rise. California could lose more than half of its coastal habitat to sea level rise.

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