In a small area of northwestern Venezuela, where the Catatumbo River meets Lake Maracaibo, you’ll discover one of nature’s most spectacular phenomena - the Catatumbo lightning.

Known as Relámpago del Catatumbo, or “the everlasting storm,” this wondrous natural light show rampages through the sky for up to 160 nights a year, for as long as 10 hours at a time. And it’s not just the odd fierce strike here and there, oh no, this storm produces as many as 280 per hour. That’s a record breaking 1.2 million per year. The persistent flashes are so bright that they can be seen for up to 250 miles and consequently were used for centuries by Caribbean navigators in colonial times, resulting in the nickname “Lighthouse of Catatumbo.”

To add to the beauty, the flashes appear a variety of striking colors, from reds and oranges to blues and purples, due to the presence of varying amounts of dust particles or water vapor in the atmosphere. Some say that the Catatumbo lightning is unique because it does not produce thunder, but that is a myth. The storm occurs at such a distance from the observers, some 30-60 miles (50-100 km) from Lake Maracaibo, that the thunder cannot be heard. It is rare to be able to hear thunder if you are located 15 miles (25 kms) or more from the lightning strike.

The Catatumbo lightning has also cropped up in history a few times. Spanish poet Lope de Vega wrote a poem in 1597 entitled “The Dragontea” which describes how Sir Francis Drake’s 1595 attempt to take over the city of Maracaibo by night was thwarted by “flames, which the wings of night cover.” The lightning illuminated the English ships and thus city defenders were alerted of the upcoming attack. A similar situation then happened in 1823, during the Venezuelan War of Independence, as Spanish fleets were exposed by the storms and then defeated.

The lightning is also thought to be the largest producer of tropospheric ozone in the entire world. Some believe that this is helping to replenish the ozone layer; however, most argue that the ozone produced never reaches this high.

Despite its fame, little is actually known about the precise mechanisms behind this phenomenon. The ancient Yukpa people, an indigenous community that is still found today on both sides of the border between Colombia and Venezuela, believed that the lightning was triggered when fireflies encountered ancestral spirits. Slightly more modern ideas include methane, the topography of the region, and uranium.

Numerous scientists traveled to the area in the 20th and early 21st century in order to investigate the mechanisms behind the lightning. In 1911, Melchor Bravo Centeno postulated that the thunderstorms are likely caused by closed wind circulation in the region, and it seems that this is the most plausible explanation.

The topography of the area is unique because two walls of mountains surround Lake Maracaibo from three sides. When hot, moist air from the Caribbean flows into the Maracaibo basin from the only side that is free of mountains, it is met with cooler air from the Andes and is forced upwards. The vapor then begins to condense, forming clouds that discharge electricity and ultimately, lightning is produced. The whole process is fuelled by the constant supply of warm, moist air in the basin that results from evaporation of the lake by the scorching equatorial sun.

Venezuelan scientist Andrew Zavrotsky also visited the area several times in order to investigate the lightning and discovered three epicenters: the swamps of Juan Manuel de Aguas National Park, Claras Aguas Negras and a location west from the lake. He also believed that uranium in the bedrock may be contributing to the lightning, but so far there is no evidence to support this hypothesis.

Another popular idea is that methane is contributing to the storms. The Maracaibo basin is perched on top of one of South America’s largest oil fields and some believe that the methane gas rising through the swamps may play a key role in producing the lightning, perhaps by increasing the conductivity of the air, but this hypothesis has generally been rejected by atmospheric scientists. This is because the atmospheric concentration of methane in the region is not high enough to exert such an effect.

While the exact cause of the Catatumbo lightning is unknown, it is probable that it is the result of the unique topography of the region combined with closed wind circulation and heat. Still, the storms remain an utterly spectacular sight and perhaps warrant addition to the bucket list.