CENTUMCELLÆ, (anc. geog.), Trajan's villa in Tuscany, on the coast, three miles from Alga; with an excellent port, called Trajanus Portus, (Ptolemy); and a factitious island at the mouth of the port, made with a huge block of stone, on which two turrets rose, with two entrances into the basin or harbour, Rutilius. Now Civita Neechia. E. Long. 12. 30. N. Lat. 42.