Costa Rica is home to only two protected pre-Colombian archaeological sites, including the larger and better known National Monument of Guayabo. But the less familiar Finca 6 holds greater interest as a subject of study due to its major feature, the mysterious Diquís stone spheres.

Although spheres exist at four different sites in Costa Rica, Finca 6 is the only one open to the public. Located in the flat alluvial plain and wetland of the upper Osa Peninsula, near Sierpe, the land area is characterized by heavy sedimentation. Fortunately, this enabled the Diquís stone spheres and other structures to be very well preserved below a 1.5-meters-thick layer before they were unearthed, usually by farmers clearing or digging a field.

As one of the few places where spheres were discovered “in-situ” (undisturbed), Finca 6 was declared a UNESCO World Heritage Site in 2014.

No one knows their purpose.

Why did they exist?

The most fascinating fact about the Diquis spheres: no one knows their purpose. There are many theories but little proof. Some believe they denoted rank or kingship, others think they were merely status symbols or perhaps tribe symbols.

Astronomical importance has been suggested by a set of spheres discovered at Finca 6 that align themselves with the sun in mid-April and mid-August. This alignment on what is called the subsolar point — the sun is 90 degrees directly overhead — occurs only in tropical latitudes and  is most noticeable for the total lack of shadows.

But for all these and other theories, mystery still surrounds the spheres. What is known for certain is that they are old — about 2,000 years old. Their surface is polished and their shape is perfectly spherical, ranging in size from that of a bowling ball to two meters or more in diameter.

The spheres are comprised of volcanic basalt, Andesite or sandstone, none of which is found at the Finca 6 site, but much further into the mountainous Dota region. This is where scientists believe the spheres were quarried before being either carried, or floated down streams, to the settlements below.

Visiting Finca 6

Finca 6 is a National Museum-run site located at Finca 6 de Palmar Norte in the Osa Peninsula. Take route 34 eastbound or route 2 westbound to Palmar Norte, then cross the big bridge heading south. Turn right onto route 223 towards Sierpe. Drive seven kilometers before turning left onto a dirt road (marked by a sign), just before a blue bridge. Continue until you reach the museum parking lot.

Public bus transportation from San José is available via TRACOPA (Sierpe destination). Phone 506 2221-4214 or visit

The Finca 6 visitor’s center is constantly changing. The original was replaced by a new one only to have it damaged by Tropical Storm Nate. Now, a third and larger one has completed construction. 

If you go: 

    • Admission for non-residents is $6 for adults and $4 for students. For residents it’s 1,000 colones.
    • Hours are 8 a.m. to 4 p.m., Tuesday through Sunday. 
    • GO EARLY to avoid daytime hot temperatures improve your chances of seeing birds, monkeys and other wildlife in the park. Walking trails take about 30 minutes to visit all of the five different site areas.
    • Wear long pants, sunscreen and repellent.  
    • English-speaking tour guides are available, but you may have to wait.
    • Recommended: Watch the video and read the information in the museum en route to the spheres site. This may be sufficient to enjoy your visit without a guide.

The Spheres and The Simpsons

Costa Rica’s legendary Diquis stone spheres have a new claim to fame after being featured in episode no. 669 of Fox TV’s The Simpsons. Aired on Sunday, November 17, 2019, “Livin’ La Pura Vida” took the yellow cartoon family on the kind of Costa Rican adventure only the show’s creators could dream up.

Over the years, the relocation of many uncovered spheres in Costa Rica has made them anything but a well-kept secret. They can be found in front of government buildings and even hotels, while the black market for spheres has also given rise to modern notoriety.