The incredible Seljuk-era walled fortress of Qal’eh Rudkhan defends a steep, wooded spur of the Alborz mountains some 50km south of Rasht and makes a lovely day trip, especially when coupled with a visit to nearby Masuleh. From spring to autumn, the winding, vertiginous ascent through lush forests, moss-clad streams and evenly spaced teahouses should take about an hour. Start early in peak season, as the fortress is popular with locals and foreigners alike.