CREATE TABLE table_37790 ("County" TEXT, "Irish name" TEXT, "County town" TEXT, "Most populous city/town" TEXT, "Province" TEXT, "Region" TEXT)

Irish name of an d n (contae an d in) has what county town?
SELECT "County town" FROM table_37790 WHERE "Irish name" = 'an dún (contae an dúin)'
SELECT "County town" FROM "table_37790" WHERE "Irish name" = 'an dún (contae an dúin)'