Nielson Field was an airport in the Philippines. It was Asia's first airport. It opened in 1937. It was set up by Laurie Reuben Nielson, a New Zealander. It was converted into a military airbase during World War II. It was built on 42 hectares of swampland. In 1948, it stopped operating and was converted into a business district. Its runways became the main avenues. Its radio or control tower is still standing as a museum. Today this district is the Ayala triangle in Makati City.