Mercury Desert is a desert just east of the Sandopolis desert, south of the Sand Hill (Sonic Forces Green Hill desert), west of the remaining Blast Hill, and north of the Mirage Saloon desert. It is full of mercury deposits and is very dangerous to enter. Mercury oases tend to cover about 35% of the location, so poisonous mercury gas is common and very dangerous. Many have built efficient settlement in the desert (with only few living in the desert for long)
However, since the desert's purification, civilization has thrived in the desert, with industrious technology and ecologically friendly energy sources (mainly solar energy, due to the extreme desert heat), by an empire named the Epotheer Empire.
The Mercury Desert is susceptible to acid floods and mercury floods, when it starts storming (which is rare, but more common than in any desert). The desert is indicated by a gray mist (the toxic mercury gas). Cinnabar is often located in multiple locations, which intoxicates the water.
Blast Hill Zone (40,000,000 years ago-2,000,001 years ago)
Previous to the dryup, the desert was an animal-filled paradise named the Blast Hill Zone.
Creation (2,000,000 years ago)
The Mercury Desert was in fact not a desert, but what ancient beings call "Dry Hill Zone". The zone started losing it's water and drying up over the thousands of years passing, until eventually becoming an ordinary desert without any special qualities.
Population (1,500,000 years ago)
The beings built settlements and suffered in the scorching hot summer heat. To solve this, they insulated the roofs with some sticks and sand on top. However, their main problem was non-anthropomorphic animals entering their home and causing chaos.
The Great Rain Period (1,000,000 years ago)
The Great Rain Period had struck the Mercury Desert, named simply, The Desert, and caused it to give increased birth to cacti and even small shrubs and plants. But, the population in the desert was worried, because some claimed to have glimpses of water creatures. Floods struck the location. But, after one person died from radiation, they started getting out of there immediately.
The Toxication (300,000 years ago)
The oases left of the Great Rain Period had started to turn silvery-gray and become toxic. The remaining survivors of these toxic gases drank the water and died due to the intense radiation. Then, one survivor (somehow having the ability to survive extreme radiation amounts) looked down at a massive deposit of cinnabar below many oasises. Some cinnabar also appeared on the surface too. As years passed, the desert became foggier until it was hard to see. It was also becoming more toxic and even the one survivor was susceptible to the immense radiation. But not with the hazmat mask (not invented until 300 years ago)
The Construction (20 years ago)
Doctor Robotnik entered the dangerous desert with a hazmat mask and decided to build a giant factory in the center of the huge mist. This factory started to smogify the desert, speeding up its very slow increase of radiation. Over 750,000 animals were kidnapped in a small anti-radiation capsule and trapped in a high-security prison.
The Destruction (5 years ago)
When Sonic has heard about the kidnapping of the animals, he noticed the poisonous nature of the desert and, speedily, found a gas mask. Treading through the dangerous desert and the high-security defense systems of the prison, he was able to free over 3/4 of the animals that were jailed. The rest of the animals found a way out sooner as the factory began to blow. As the factory blew, it blew a mysterious dust that removed the poisonous properties of everything in the desert. The name was changed from the Mercury Desert to the Paradise Desert 3 years after.
The Second Population (3 years ago - present)
Boolobes have recently populated the area and already were able to fit 5 million Boolobes in the Epotheer Empire.
It is currently being infiltrated by the Epotheer Empire as territory of their own.