Archaeological feedback | 229 LEA MAX – multi-purpose gradiometer array in the fields of the Kaikos valley (Bergama, Turkey) Cornelius Meyer a , Henning Zöllner a , Dana Pilz a , Barbara Horejs b and Albrecht Matthaei c KEY-WORDS: magnetic prospection, multi-sensor techniques, geoarchaeology During the past decade magnetic surveys using multi-gradiometer arrays have proven to be an eminently suitable tool for the investigation of extensive archaeological sites and landscapes. By means of vehicle-driven devices areas of 10 to 40 ha can be surveyed at high data density in one day. However, in archaeological practice many factual constraints lurk not only beneath the surface. Mediterranean landscapes with long human settlement history are especially often charac- terised by intensive agricultural use and sprawling industrial and construction activity. In many cases, archaeological sites are already half-destroyed or in danger of imminent total destruction. Thus, archaeologists must not lose time to survey whatever still remains of these records of history. Investigation areas vary in size and in surface conditions. Additionally, in these archaeological landscapes many sites are still hidden in remote places, hardly accessible to motor vehicles. Geophysical prospection projects under these preconditions also require versatile measuring equipment and case-by-case approaches. The geophysical investigations in the Kaikos valley (Bakırçay), the archaeologically very rich landscape between the ancient Greek city of Pergamon in Aeolis and its port Elaea, are textbook examples. Between 2009 and 2011 a number of Classical sites were investigated within the frame of the DFG-funded SPP (priority program) “The Hellenistic polis as a manner of life”. The fieldwork was directed by Dr. Albrecht Matthaei from LMU Munich University (Zimmermann 2012; Mattthaei 2014). Parallel to it, a survey program of prehistoric sites in the environs of Pergamon started in 2010. In this case, six prehistoric sites, partly recorded earlier (Driehaus 1957) and partly newly dis- covered, were surveyed with geophysical methods. The main objective of the survey was to study a Eastern Atlas GmbH & Co. KG, Berlin, Germany b OREA Institute for Oriental and European Archaeology, Austrian Academy of Sciences, Vienna, Austria c Fraunhofer-Institut für Bauphysik IBP, Valley, Germany Archaeologia Polona, vol. 53: 2015, 229-232