Washington's tallest building - at 76 stories - is home to the Columbia Center in the heart of Seattle's financial district. Situated on the 42nd floor of Columbia Tower, one most prestigious business addresses, it is well positioned to serve a city that, through its port and international airport, is a major gateway to Asia, Alaska and the rest of the world. Elliott Bay is a huge commercial asset as one of the finest deep-water ports in the world. The fifth largest container port in the United States and the twentieth largest in the world, it can accommodate ships up to 1,400 feet in length. Seattle-Tacoma International Airport is served by more than a dozen cargo carriers and helps sustain the tourism industry. The city's diverse economy includes companies using advanced technology in computer software, biotechnology, electronics, medical equipment and environmental engineering. Building amenities include shops and restaurants plus a range office spaces.