Venus is the second planet from the Sun and Earth's closest planetary neighbor. Even though it's not the closest planet to the Sun (that's Mercury), it is the hottest planet in our entire solar system.
Why is it so hot? Venus has a thick, toxic atmosphere filled with carbon dioxide, completely shrouded in thick, yellowish clouds of sulfuric acid. These clouds trap heat like a giant greenhouse, making the surface hot enough to melt lead!
Venus also spins backwards compared to most other planets, including Earth. And it spins so slowly that a single day on Venus is longer than its entire year.