The Crimean Tatars attacked again in 1591, but this time were held back by new defense walls, built between 1584 and 1591 by a craftsman named Fyodor Kon. In 1592, an outer earth rampart with 50 towers was erected around the city, including an area on the right bank of the Moscow River. As an outermost line of defense, a chain of strongly fortified monasteries was established beyond the ramparts to the south and east, principally the Novodevichy Convent and Donskoy, Danilov, Simonov, Novospasskiy, and Andronikov monasteries, most of which now house museums. From its ramparts, the city became poetically known as ''Bielokamennaya'', the "White-Walled." The city's limits as marked by the ramparts built in 1592 are now marked by the Garden Ring.