Meng Meng and Jiao Qing appear to have made themselves at home in Berlin, where measures have been taken to ensure their surroundings are to their liking. That includes lots of bamboo, a favorite food of the black-and-white bears.

Meng Meng and Jiao Qing received a warm welcome from Chancellor Merkel at an official opening ceremony on Wednesday. The Berlin Zoo has created a special Panda Garden habitat for the giant pandas in the hope of making them feel at home in the German capital. Berlin is the only zoo in Germany to house panda bears.

In Germany on official business just ahead of the G20 summit in Hamburg, China's President Xi Jinping met with Merkel before taking part in the official ceremony. The giant pandas are on loan from China after Germany struck a deal two years ago to secure their addition to the Berlin Zoo.

Despite the presence of two of the world's most powerful leaders, the panda bears stole the show. Merkel said the long-awaited bears were "two very nice diplomats" which serve as "special ambassadors between our two nations."

Visitors to the Berlin Zoo will be able to see the highly-anticipated panda bears beginning Thursday.

While there are high hopes that they may mate, any offspring produced in Berlin will need to be returned to China once old enough to survive without its mother.

The new additions to the Berlin Zoo seem to be feeling right at home in their newly renovated Panda Garden. The last panda resident at the zoo, Bao Bao, died in 2012, so his home had to be updated for the happy pair, the only pandas in Germany. They are on loan from China for 15 years.

Crowds eagerly awaited the arrival of the two giant pandas when their plane touched down at Schönefeld Airport on June 24. The long-awaited bears received a royal reception on the runway before being brought to their new home in the Berlin Zoo.

Trees for climbing, an artificial river, species-appropriate plants - preparations for Chinese pandas Jiao Qing (pictured) and Meng Meng have been in high gear at Berlin's Zoological Garden. The Panda Plaza is now up and running after the two arrived on a first-class flight from China June 24. Such luxury for animals has not always been the case. Here's a look back at the history of German zoos.

Professor of zoology Martin Hinrich Lichtenstein was so enthused with the Zoological Garden in London that he wanted to build one himself. In 1841, he was able to convince Friedrich Wilhelm IV to do it. The King of Prussia decreed that some 22 hectares (54 acres) be sectioned off from Berlin's Tiergarten and turned into Germany's first Zoological Garden.

By 1845, two coatis, three Arctic foxes, a red jackel, two badgers, 24 monkeys, and three bears from Siberia were living there. In 1846, lions and tigers were moved into their own building. The first elephant came onto the scene in 1857, in 1861 the first zebra. Yet sadly, there was a high animal mortality rate.

The Schönbrunn Zoo in Vienna took a completely different and much grander approach. In 1906, the first elephant to be conceived in a zoo was born. By 1914, Schönbrunn was one of the largest zoos in the world, with 3,500 animals from 717 species. It became a role model for the Berlin Zoo. Today, Schönbrunn is one of the oldest existing zoos in the world and allegedly the most visited in Europe.

Many zoos sprung up in German-speaking countries in the second half of the 19th century. After Berlin, Frankfurt, Cologne, Hamburg, Basel, and Leipzig followed suit. But Prussian King Wilhelm IV had already created his own wildlife park back in 1571, which he used not only for hunting - he also allowed nature researchers to live there.

Many compounds, such as this Antelope House in Berlin's Zoological Garden, were built in the 19th century and attempted to reflect the exotic origins of the animals. But as aesthetically appealing as they may have been, they were not always species-appropriate. Still, they cannot be altered because building conservation laws stand in the way.

In the 20th century, zoos popped up all over Germany, and aquariums opened up as well. Monkey parks, ocean parks and bird parks became a craze, and people could even drive their cars or take the bus through safari parks. With the economic boom of the 50s and 60s in Germany, even smaller cities could open zoos or animal parks.

Post-war Germany saw a boom in zoos, with people eager to witness exotic animals. Zoos became living classrooms, but a remotely species-appropriate way of keeping the animals wasn't a priority. Cages and trenches separated lions, tigers and elephants from visitors. It wasn't until the 1970s that research revealed more insight into the psychology of animals, and zoos began altering their designs.

A milestone in zoo design are panorama areas such as the one Carl Hagenbeck built in Hamburg. Rather than being stuck in cages in a systematic way, animals are kept according to "continents." Lions live near zebras, giraffes, and elephants, for instance, in the "Africa" region of the zoo. Green zones at the Cologne Zoo (pictured) ensure that animals are kept similarly to their natural habitat.

Small cages and concrete pens are becoming more and more a thing of the past. Yet how zoos develop in the future depends on smart management. Some zoos, such as in Frankfurt, for instance, have decided to close their elephant houses. As a small zoo in the inner city with just 11 hectares (27 acres), it simply could not provide the animals with enough space.

Zoos breed species and aim to return them to the wild. They are also involved in environmental conservation and educate visitors about their habitats. But zoo opponents say that to keep certain animals species alive only in zoos is unethical. Instead, focus should be placed on keeping their natural habitats intact. Pictured is a newborn platypus named Mackenzie.

Zoos in Germany get more visitors than sporting events. Nowadays, they're more like entertainment parks with adventure playgrounds, themed restaurants and merry-go-rounds. A little farm at the Cologne Zoo recently opened, where visitors can pet cows and goats. Zoos are now irreplaceable, not only for visitors to reconnect with nature, but also to preserve certain endangered animals.