1. An analysis of the meaning of the terms aedes, templum, delubrum, fanum, sacrarium, lucus: even if these terms are often interchangeable, the precise meaning of each can be established. 2. On the basis of the original meaning of templum (a ritually delimited space), it is proposed to apply this term to the platform with the aedes of Fortuna and of Mater Matuta, the ‘area sacra di S. Omobono’, and also to the ‘podium’ of the temple of the Capitoline triad. A typological comparison may also be made between these two templa, which were perhaps constructed at almost the same time. 3. The typology of the temple inside an area bounded by a portico may also be referred to the templum. The numerous variants of this typology are examined. 4. After a consideration of templum in its more specific sense of locus augurii aut auspicii causa definitus, the two auguracula—on the arx and the collis Latiaris—are examined in particular, and new identifications are proposed for them. 5. The term lucus raises the question of extra-urban cult sites. A scheme of classification is proposed: shrines of purely local importance, and sanctuaries repeating city cults in more distant sites (political motivation may be detected). For cult sites very close to the city the problem is more complex, involving in part the pomerium, evocatio, and the introduction of foreign cults.