Nardaran is arguably the most interesting of all the Absheron towns, though you'd never guess it if you just drove through.
The old centre of town atop a steep, north-facing slope, was built around the summer palace of the 15th-century Shirvanshahs. At that time the level of the Caspian Sea was higher than today so the castle would have had an even better view of potential invaders arriving by sea. Local historians claim that the eastern approaches were simultaneously watched by a look-out post near Zagulba linked to Nardaran by an improbably long tunnel, now closed and mainly collapsed.
Nardaran and bigger Mashtaga to which it now clings as a virtual suburb are Azerbaijan's most piously Muslim towns. Backstreet walls are daubed with Islamic slogans and cartoons designed to guide moral behaviour. Though hardly Iran-strength fanaticism, you'll see a fair few women in chador.
The gigantic Rehime Khanim Mosque was built between 1997 and 1999 on the site of the former khan's summer palace and is arguably the most impressive religious structure in Azerbaijan. But what draws visitors is the little subterranean tomb beneath which the faithful peep through a tiny window under an artificial rose to offer prayers to the grave of Rehime Khanim, another sister of the 7th Imam (like Okuma/Herkume at Bibi Heybat). A donation here is considered an effective approach to conquering infertility. Women visitors should wear a scarf, you can borrow one from the shoe deposit desk.
In the winding streets and alleys nearby you'll find several other mosques most notably the blue-domed Aga Mosque with its fortified round tower minaret. A two-minute walk beyond is a modest medieval castle tower whose simple crenellated tower (built in 1301) and inner curtain wall have been heavily restored, while most of the outer defences have long since vanished. The Shah Abbas Caravanserai has been reduced to one small, insignificant building in the corner of a private vegetable garden.