Registan became the city square when the life in Afrosiab stopped. Since that time Registan was reconstructed several times. Today it is surrounded by the three medreses Ulugbek, Shirdor and Tilla Kari. At night the guards will let you in for $5 or $10. They may suggest you climb up onto the roof of one of the Madrasah, which is not advisable, dangerous, dusty and with limited interest.