BLOCK71 Singapore, commonly known as "Blk71", is a factory building located in the Ayer Rajah Industrial Estate of one-north, Singapore. The Economist referred to BLOCK71 as the heart of Singapore's technology start-up ecosystem and the world's most tightly packed entrepreneurial ecosystem. BLOCK71 has built up a strong innovation and entrepreneurship community, where entrepreneurs, investors, developers and mentors within the interactive digital media space are in close proximity to each other. BLOCK71 is home to more than 100 start-ups, venture capital firms and tech incubators. It is also located near other technology hubs within Singapore, such as the Fusionopolis, Biopolis and National University of Singapore (NUS).