Around the start of the 20th century, the first heated fruit storehouses were constructed, and in 1928, a refrigerated herring warehouse designed by Fritz Schumacher was built. The city of Hamburg has built a new concert hall on top of an old warehouse, called the Elbphilharmonie. It is a new landmark for the city, but has been plagued by vast cost overruns and its construction was about six years behind schedule. It was opened on 11 January 2017. The area is served by the Katharinenschule, an elementary school. It is the home of HafenCity University, a new school focusing on architecture and urban planning. The area is currently home to the German headquarters of Kühne & Nagel, an international shipping conglomerate, the Spiegel Group's new headquarters on the Ericusspitze, and Unilever. Greenpeace opened its new headquarters in Hafencity in 2011. The Hamburg-America Center opened its doors in 2009. The Honorary Consulate of the Kyrgyz Republic (Kirgisistan) established in Hamburg in 1995 is located at "Am Sandtorkai 77". At Strandkai, cruise ships can berth at Hamburg Cruise Center HafenCity. The area is served by a newly constructed underground line, the U4, which was completed in 2012. The line features two new stations: Überseequartier and Hafencity University. Because HafenCity is subject to periodic flooding from storm surges, using innovative flood protection technologies has been an important part of its redevelopment. The threat from flooding is even more grave due to the predicted effects of climate change. While dikes were initially considered to shield the islands from storm surges, it would have been impossibly expensive and taken away from the view. Instead, there are strict flood-protection rules in places within the special development zone, such as requiring new roads and public spaces to be built on sand terraces over above the normal high-tide line. Buildings along the shore remain at their original level but must be waterproofed up to the elevated-road level. In addition, shore-adjacent buildings are required to have an entryway allowing access to the -high road level so that they remain accessible during times of flooding. Although the design has been expensive, it has been recognized as one of the more innovative flood protection innovations in use today.