The whole book of Revelation is a circular letter addressed to seven specific churches: Ephesus, Smyrna, Pergamum, Thyatira, Sardis, Philadelphia, Laodicea (1:11; cf. 1:4; 22:16). They are probably named in the order in which they would be visited by a messenger starting from Patmos and travelling on a circular route around the province of Asia. But many misreadings of Revelation, especially those which assume that much of the book was not addressed to its first-century readers and could only be understood by later generations, have resulted from neglecting the fact that it is a letter.