This volume XI of the Preliminary Reports gives a short overview of the activities of the Belgian Archaeological School in Greece during the years 1983-1990 and contains some short studies of 1) the masonry in domestic and rural constructions in Thorikos: a limited attempt to establish a foundation for a local typology and more accurate chronology; 2) an identification and dating of cooking ware vessels (c. 100 items with drawings) coming mainly from the Insulae 3, 10 and 11; 3) a Roman furnace found in the Theatre Necropolis: the clarification of its function: a) investigation of its structure, b) examination of the composition of the slags and c) the chemical analysis.