Europe

Vertical farms, food trucks, tropical forests and the supermarket of the future are on display at Expo 2015 in Milan. Exhibits from 145 countries focus on how to feed the planet sustainably.

The inmates have private cells and dine with the guards. Norway spends three times as much as the U.S. per prisoner. Norwegians say it pays off, with less than half the U.S. recidivism rate.

The system was considered a triumph by the Soviets, but was built by the same ruthless means that helped cause a famine, which killed millions in the 1930s.

President Obama will award the Medal of Honor posthumously to Henry Johnson, an African-American soldier whose combat bravery occurred during World War I, but whose actions were ignored for decades.

A bold statue has taken up residence in London's iconic Trafalgar Square — part of a public art project that's been going on for more than a decade. The skeletal horse replaces a giant blue rooster.

While Ukrainians fear another offensive, Russian President Vladimir Putin has signed a measure saying that Russian military casualties during peacetime will now be considered a state secret.