The medieval popular quarters of the city, situated mainly around the Capitol, were largely demolished between the end of the 19th century and the fascist period, but many notable buildings still remain. Basilicas dating from Christian antiquity include Saint Mary Major and Saint Paul outside the Walls (the latter largely rebuilt in the 19th century), both housing precious fourth century AD mosaics. Notable later medieval mosaics and frescoes can be also found in the churches of Santa Maria in Trastevere, Santi Quattro Coronati, and Santa Prassede. Secular buildings include a number of towers, the largest being the Torre delle Milizie and the Torre dei Conti, both next to the Roman Forum, and the huge outdoor stairway leading up to the basilica of Santa Maria in Aracoeli.