Tourists feast their eyes on majestic seas and glorious greeneries. But natural phenomenon isn't always as perfect as the tourist-favorite beach spot or the picture-perfect garden on the hill. Sometimes, nature has surprised people with otherworldly sights make eyes pop with awe.

Here are five of the strangest-looking - but visually stunning - tourist spots in the world.

1.     Blood Falls, Antarctica

Geologists have discovered the five-story blood-red waterfall pouring from the Taylor Glacier in Antarctica's McMurdo Dry Valleys in 1911. Creepy as it may look, the red liquid is not real blood, and is not caused by red algae as Antarctica explorers once thought.  

According to Atlas Obscura, the high salinity of the subglacial lake beneath the Taylor Glacier has given it a scarlet tint.

The extremely saline water trapped under the Taylor Glacier, isolated from light, heat and oxygen. As the water trickles out of the glacier fissure, it reacts with oxygen to create the blood-red hue.

2.     Frozen Methane Bubbles, Canada

Methane gas bubbles beneath the Vermillon Lakes in Banff National Park in Alberta, Canada, often in winter, making it look like a frozen sea of flying saucers.

According to The Guardian, the methane bubbles normally break the surface but freeze during winter. The gas is emitted by bacteria after they have consumed dead organic matter and is fairly harmless. However, the bubbles created by the gas may explode once lit.

3.     Sailing Stones, U.S.

The "Sailing Stones" in California's Death Valley National Park are heavy stones that appear to move across the dried lake bed of Racetrack Playa, leaving a trail as they go.

According to Live Science, people speculate aliens to be involved in the phenomenon. But NASA scientist Ralph Lorenz tried to put sense into it in 2006 and developed a model that could explain the movements.

Lorenz found that in winter, Racetrack Playa fills with water and the stones are encased in ice. Because of the ice's buoyancy, even a faint breeze could move the frozen rocks across the sand at the bottom of the lake, and the movements leave tracks.

4.     Kawah Ijen Lake, Indonesia

Tourists are fascinated with stunning turquoise-hued caldera lake at the Kawah Ijen volcano's summit.

According to Geology.com, the high acidity and high concentration of dissolved metals are responsible for the water's turquoise color. The lake is also the largest highly-acidic lake in the world, with a pH of as low as 0.5.

5.     Hidden Beach, Mexico

Vacationers dreaming of a clandestine beach spot tucked away from prying eyes should stop by the Playa Del Amor or Hidden Beach in Mexico.

According to Mail Online, the idyllic paradise was actually caused by a bomb explosion in the early 1900s. During that time, Mexico started testing bombs in the Marieta Islands, which is where Playa Del Amor is located, resulting in a massive hole on the island.

Over the years, the hole was filled with sand and water, creating a picturesque, secluded beach spot.