On the orientation of two Roman towns in the Rhine area

Abstract

The aim of the present paper is to extend the archeoastronomical study sample on the orientation of Roman cities to the analysis of a number of cases in the Rhine area. The starting point is a study of the orientation of Augusta Treverorum (present day Trier; Goethert, 2003). Goethert assumed that the orientation of the decumanus maximus was towards sunrise at the autumn equinox, on September 23rd as the dies natalis of the city. This event would deliberately coincide with the anniversary of the birth of Augustus, and would have determined the establishment and orientation of the new urban layout. However, our in situ measurements of the orientation of the urban network at several sites of the Roman town rule out this hypothesis. We find an orientation that is more in line with those documented for other Roman cities and camps elsewhere in the Roman provinces (Gonzalez-Garcia et al., 2014; Rodriguez-Anton et al., 2016). Moreover, measurements made in the Lenus Mars temple indicate a recurrent phenomenon of cultural hybridization. Here the temple, located outside the city walls on the west bank of the river Moselle, combines a possibly Celtic orientation with Roman symbolic beliefs. In reality, the alleged orientation towards the dies natalis of Augustus is verified for Cologne. There are a number of circumstances that make this choice logical for a city that was initially planned as the capital of the Augustan province of Germania and the seat of an ara of imperial worship.