The most salty sea in the world is the Dead Sea. Here are the reasons why:

Salt Content:
- The Dead Sea has a salt content of around 34.2 percent, which is almost 10 times saltier than the average ocean.
- This high salt content makes it almost impossible for any living organism to survive in the Dead Sea, hence the name.

Geography:
- The Dead Sea is located in the Jordan Rift Valley, bordered by Jordan to the east and Israel and Palestine to the west.
- It is a salt lake that is landlocked and has no outlet to the sea, causing the water to evaporate and the salt concentration to increase over time.

Minerals:
- The Dead Sea is known for its high concentration of minerals, including magnesium, potassium, and calcium.
- These minerals have been used for centuries for their therapeutic value, with people visiting the Dead Sea for mud baths and salt scrubs.

Environmental Concerns:
- Despite its unique features, the Dead Sea is under threat due to human activities such as water diversion and mineral extraction.
- The decreasing water levels have caused sinkholes to form, posing a danger to people and the environment.

In conclusion, the Dead Sea is the most salty sea in the world due to its high salt content, unique geography, and mineral concentration. However, it is important to address the environmental concerns to protect this natural wonder for future generations.