The Beacon Stone, or Pedra da Baliza, is an isolated block of sandstone at the top of the Serra Geral in Brazil's Cerrado region. The stone once served as a marker between four states that told farmers and travelers where they were in the grassland sea.

"The Cerrado used to cover about one-fourth of the Brazilian territory, and now more than half the entire Cerrado is already lost to agriculture," Conservation International biologist Cristiano Nogueira said.

• More Photos in the News
• Today's Top 15 Most Popular Stories
• Free Email Newsletter: "Focus on Photography"