Due to globalisation, location have become the most important factor for firms to locate their offices and other firm supportive activities like distribution and maintenance. This have lead to land scarcity around important transport nodes like airports. This thesis will focus on several business parks around major airports to gain insight which type of business are locating near airports, what kind of location patterns exist and if there are intercontinental differences. This thesis is substantiated by comparing theory on clustering, airport land usage and the aerotropolis concept to four selected airports throughout the world in a qualitative manner. The four case studies consists out of the airports of Amsterdam, Madrid, Seoul and Dallas and are being analysed with an aerotropolis-based view. Data from the selected case studies showed a high presence of firms within high technology sectors like ICT, software and hightech manufacturing. This complies with the aerotropolis concept. Also a high presence of firms within the financial and insurance sectors are visible through the data. Although the aerotropolis concept have been a useful framework, it is not the ideal situation. This is visible in the case of Madrid Barajas airport. The airport is a big catalyst to the regional economy, but lacks a high presence of firms within high-tech sectors. Even though Madrid Barajas airport is not an aerotropolis, it is still an important factor in the location decision for firms. By looking at the data and comparing them with the aerotropolis concept it was possible to conclude that the typical sectors that are located around the selected airports are in the high technology and financial sectors. Also the location patterns are very clear by looking at these four cases. The clusters are located along the major corridors between the airport and the city centre. It was not possible to make a generalised conclusion on whether or not there is a difference between continents, but based on the four case studies there are no big differences.