This volume of the Estonian Journal of Archaeology is dedicated to the Kohtla-Vanakula (from here onwards Kohtla) site--a recent discovery of iron weapons and tools in the midst of a small meadow field in north-east Estonia. The site was discovered accidentally by a metal detectorist in 2013. The Kohtla deposit is a rare find containing ca 400 iron artefacts including hundreds of weapons and tools such as spearheads, axes, sickles, etc., deposited in the wetland context over several centuries during the first half of the first millennium AD.

The discovery of the Kohtla find and studies conducted there are unique for several reasons in the history of Estonian archaeology. First, the find itself and the following fieldwork exemplify the possibilities of fruitful co-operation between the metal detectorists and archaeologists. Second, the opportunity to conduct extensive excavations and in situ documentation of such sites is so far still a rare occasion in the eastern Baltic archaeology. Therefore we hope that our work will set an example of the various possibilities of excavation techniques as well as further analysis of artefacts which allow gaining better understanding of past depositional practices and their further interpretations. Third, the Kohtla project illustrates possibilities for interdisciplinary archaeological research combining geology, chemistry, conservation sciences, biology any many more, with the team of both local and international scientists.

There are altogether four articles in this volume discussing very different aspects of the find, its context and content, but also setting the Kohtla deposit into a wider context of the Baltic Sea Iron Age archaeology. The first by Oras et al. outlines the find itself, its story of discovery, the main results of fieldwork together with preliminary overview of different artefact types, contexts, dates and further discussions of similar finds in Estonia and in the wider circum-Baltic region.

The general paper is followed by more detailed overviews of the main artefact types discovered in Kohtla. Tvauri et al. discuss the spearhead finds, especially in relation to eastern Baltic Iron Age spearhead typology and in the light of direct AMS dates from the sockets of Kohtla spearheads. Saage et al. dedicate their paper to axe finds with a special emphasis on metallurgical analysis and identifying the production sequence of a particular socketed axe from Kohtla.

The last paper by Kriiska et al. introduces the results of environmental analysis of the site. These include various geological and micromorphological studies, but also data from historical and contemporary maps. Although currently a simple dry meadow field, there are several indicators showing that at the time of deposition, i.e. during the Iron Age, the site was probably a flooded area suggesting that the weapons and tools were initially deposited in a watery context.

Besides the papers presented here the Kohtla find has resulted in several outputs including preliminary overview research article, popular-science articles in local journals and newspapers, student projects, etc. The artefacts themselves are stored at the University of Tartu archaeological collections and are open to further analysis by anyone interested in this rare find. Additionally, curation of a selection of objects and the story of the Kohtla find is on display in the recently opened new exhibition of the Estonian National Museum in Tartu. Thus, with this special volume of research papers, we hope that we have managed to introduce the Kohtla deposit to very different audiences both in Estonia and abroad.

Finally we would like to express our special gratitude to everyone who participated in the Kohtla project both indoors and outdoors. The list of people would be vast, but we are extremely grateful to all the volunteers who helped with fieldwork in 2013, and especially a local metal detectorist club Kamerad for their cooperation. Also we are thankful to the land owner of Luharahva farm, local community and civil servants who helped us during the fieldwork at Kohtla. Further conservation work would have been impossible without the help of Kristel Kajak and Andres Vindi (University of Tartu), and without the advice given by dear colleagues at the National Museum of Denmark and Moesgaard Museum, Denmark. The excavations, conservation and detailed analysis were supported by the Estonian National Heritage Board, University of Tartu Faculty of Arts and Humanities base funding for the research of national significance, Arheograator Ltd., Estonian Ministry of Education and Research institutional research project IUT20-7, and the European Union through the European Regional Development Fund (Centre of Excellence in Cultural Theory, CECT).