The Hisar presides over an outcropping in the oldest settled part of the city. It's believed to have been built by the Galatians, but no one really knows for sure. The fortress has an inner and outer wall, the outer added during the Byzantine occupation of the city. Originally, the citadel was constructed with 20 towers, but only a few have survived to the present day. The castle in its present state was most recently restored by the Ottomans, and dates to the Selçuk period.
Today the citadel retains much of the flavor of a small Anatolian village; from its narrow winding streets, you can catch a fleeting glimpse of the home life within. If there's any architecture worth a gander in Ankara, it's within the walls of the fortress. Many of the traditional wood-beamed houses, complete with large courtyards and gardens, have been restored and converted into marvelously atmospheric restaurants. Just outside the main gate is an atmospheric open square with stands selling dried fruits and nuts. Gentrification is not yet complete just beyond the main square. As you head down the hill you'll find an eclectic mish-mash of dusty antique shops, stores selling various hardware supplies, and the odd cafe.