Little remains from the period when Qazvin was Persia’s capital, though the Chehel Sotun predates this period and was used as a Safavidroyal palace. The building, with a large pool at its front, was built in 1510 and is located in what is now the town’s central park. Chehel Sotun is attractively floodlit at night. The name Chehel Sotun means “Forty Columns” and refers to the reflection of the 20 wooden pillars of the building in the pool, which seems to double their number.

The Imamzadeh Hossein shrine commemorates Hossein, a son of Imam Reza (765-818), the seventh descendant of the prophet Muhammad and dates from the 16th century. The facade is from the Qajar period and the building is topped by a fine blue dome with a fountain pool at the front..

The Jameh Mosque, said to be built over a Zoroastrian fire temple, dates from around the 10th century or earlier, has been remodeled over the ages and has a beautiful blue dome and interior relief calligraphy. The al-Nabi Mosque is from the Qajar period (1794-1925) with four large iwans in its courtyard.