Seismic arrays, deployed in areas with high seismic activity, record ground motion during an earthquake and constitute an important means of collecting field evidence on response of soil layers. The information and data these arrays produce are crucial for verifying, calibrating and developing predictive tools employed in earthquake engineering. Given the significance of this method of data collection, the 'Istanbul urban earthquake test site' (URBANQUAKE) project set out to install and monitor seismic array networks in Istanbul, Turkey. The region has been pegged as one with a high probability of having a major earthquake in the next 30 years. Complementing the already existing horizontal Istanbul Rapid Response Network (IRRN), URBANQUAKE installed a strong motion network of vertical arrays within the city of Istanbul. These have the potential to produce a significant number of earthquake records within a relatively short timeframe. This kind of support, along with a EUR 150 000 research grant given by TUBITAK, the Scientific and Technological Research Council of Turkey, set the basis for the creation of a fully functional urban earthquake test site. All project objectives were accomplished and larger-scale financial support was secured for future actions related to URBANQUAKE activities. One example of the latter is in the envisioned creation of a centre of excellence for earthquake engineering at Boğaziçi University's Kandilli Observatory and Earthquake Research Institute. Vertical arrays were deployed in Ataköy (ATK), located close to the Atatürk International Airport, Zeytinburnu (ZYT) and Fatih (FTH). These operate in synchronisation with the IRRN and provide reference bedrock motion for the ground motions collected by the Network. An example of the utilisation of data generated by the arrays concerns investigations into the predicted and modelled site response based on detailed information about in situ soil conditions. Another project achievement was the development of a microzonation methodology that incorporates site-specific response analysis to perform damage scenarios for urban areas. Results are displayed in damage distribution maps for buildings and pipeline systems. The methodology was developed into a software package (KoeriLossV2, 2007) to provide a practical tool for assessing the seismic vulnerability of an urban area. Project efforts have been presented at various international conferences and workshops as well as in articles in peer-reviewed publications, all bringing international recognition and attracting the worldwide attention of the particular research community. Data already accumulated from the urban earthquake test site is enabling progress in the development and calibration of site-response analysis and site-specific damage scenario methodologies. Project outcomes and ongoing related efforts thus contribute a wealth of information supporting needed actions and progress in the field of earthquake engineering. Unique in Europe in terms of instrumentation and accumulated data, URBANQUAKE achievements are also set to enhance EU competitiveness in the field.