The grandfather of the Moscow Kremlin, this citadel was the 12th-century base of Prince Yury Dolgoruky, who ruled the vast northeastern part of Kyivan Rus (and, among other things, founded a small outpost that would eventually become the Russian capital). The 1.4km-long earthen ramparts of Suzdal’s kremlin enclose a few streets of houses and a handful of churches, as well as the main cathedral group on ul Kremlyovskaya.
The Unesco-listed Nativity of the Virgin Cathedral, its deep blue domes spangled with gold stars, was built in 1225 (only its richly carved lower section is original white stone, though, the rest being 16th-century brick). The inside is sumptuous, with 13th- and 17th-century frescoes and 13th-century damascene (gold on copper) west and south doors.
Within the kremlin, the Archbishop’s Chambers (Архиерейские палаты) house the Suzdal History Exhibition, which includes the original 13th-century door from the cathedral, photos of its interior and a visit to the 18th-century Cross Hall (Крестовая палата), which was used for receptions. The tent-roofed 1635 kremlin bell tower (Звонница), directly across the yard from the cathedral, contains additional exhibits, including the 17th-century Jordan Canopy (Иорданская сень), the only one of its kind left in Russia; every January on Epiphany Day, this 28m-tall painted wooden structure would be placed over a cross-shaped hole in the ice on the Kamenka for the annual rite of blessing the river water.
To the southwest, between the cathedral and the river, is the 1766 Nikolskaya Wooden Church (Никольская деревянная церковь), which was moved to Suzdal from a nearby village in 1960. Other rural wooden buildings were subsequently moved for preservation to the excellent Museum of Wooden Architecture & Peasant Life, across the river.
If you don't want to see all of the exhibitions, you can pay for admission to the cathedral separately; to walk around the grounds only costs R50 (children get in free).