A rare Mayan solar phenomenon will draw residents and visitors to a coastal eco-park in Cozumel on Thursday evening, when the sun aligns perfectly with the upper window of the ancient structure known as El Caracol.

The event will begin at 6 p.m. at Punta Sur Eco Beach Park, a large ecological reserve at the southern tip of Cozumel, Quintana Roo, about a half-hour’s drive from the island’s cruise ship terminals at San Miguel.

The alignment, visible only under clear skies, highlights the astronomical precision achieved by the Maya centuries ago.

“This type of alignment in pre-Hispanic structures has been significant for the consolidation of archaeoastronomical studies,” said Jesús Benavides Andrade, director of the Punta Sur park.

The experience, he added, offers “a unique experience of connection with the ancestral legacy of the island.”

El Caracol — a domed building dating back roughly 600 to 800 years — once served as a navigational marker for Maya travelers along the Caribbean coast. The structure’s uncommon cupola distinguishes it from other Mesoamerican buildings, researchers note.

The phenomenon occurs twice a year, typically in February and October, when the sunset or sunrise corresponds precisely with the tower’s upper opening.

Punta Sur Eco Beach Park is a protected park noted for its biodiversity, sustainability efforts, wildlife viewing areas, Mayan ruins (El Caracol) and Celarain Lighthouse.

Its beaches, lagoons, mangroves and low forests cover about 1,000 hectares — about three times the size of Manhattan’s Central Park.

This week’s alignment will mark the latest opportunity to observe one of the Maya civilization’s most striking examples of solar engineering, said Juanita Alonso Marrufo, director of the Cozumel Parks and Museums Foundation (FPMC).

The event, she said, strengthens the sense of identity and pride in the historical and cultural heritage of Cozumel, adding that it’s in line with the New Agreement for the Well-being and Development of Quintana Roo promoted by Governor Mara Lezama Espinosa.

Weather permitting, that “historical and cultural heritage” will quite literally shine through at sunset on Thursday, April 16.

Admission is free for those who register in advance at parquepuntasur@cozumelparks.org.

With reports from Quintana Roo Hoy and Quadratín Quintana Roo