in Qazvin You need at least 1 day to visit:

The oldest part of jame mosque of Qazvin  is said to have been constructed by the orders of Harun al-Rashid in 807CE. Later additions were made, the last being during the late Safavid era. The double layered main dome of the mosque is from the Seljuk era, and is locked to the public. It houses some precious examples of relief calligraphy from medieval times. Renovations have also been carried out on many sections of the mosque.

The foundation of the mosque is laid on a Zoroastrian fire temple.

In spite of the devastating Mongol invasion, the mosque still stands today in its full glory. It is still in use. Parts of the mosque have been turned into a public library.

The mosque also contains a Shabestan (parayer hall) and Ab anbar (water reservoir), both now under the protection of Iran’s Cultural Heritage Organization.

Part of the complex caught fire on 28 January 2013. Half of the complex was burnt and destroyed by the fire.

The Imamzadeh Hossein is the grave mosque of a son of the 8th Imam Ali al-Ridha in Qazvin, Iran that the Safavids – Shah TahmaspI built in the mid-16th century as a pilgrimage center.

The namesake of the tomb is the biennial deceased son of Imam Hossein. This passed in transit with his father to Khorasan in Qazvin in 821 and was buried at the site. Later more people were buried from the Safavid dynasty bib. Tahmasp I, who had his seat of government in Qazvin, built the tomb. His daughter Zeynab Begum expanded it in 1630, as is testified by a tile inscription.

The Sa’d al-Saltaneh Caravanserai is a large Caravanserai located in the city of Qazvin.

Built during the Qajar era, the caravanserai is one of Persia’s best preserved urban caravanserais. The builder (patron) of this large caravanserai was a person by the name Sa’d al-Saltaneh Isfahani  for whom the caravanserai is named after.

The caravanserai is built on a square plan, has 4 iwans facing a courtyard. The interiors are decorated with Muqarnas and Rasmi bandi.

The Hujrehs, or the rooms for the travelers, are situated one meter above the courtyard ground level. The Hashti behind the southern iwan has the largest gonbad, with 4 semi-domes adjacent to it.

1 more day to visit:

Alamut  is located 150 km in  the northeastern of Qazvin and is built on top of a high rock reaching 2163 m above sea level near the Gazor Khan Village. The rock is 200 m high and covers an area of 20 hectares; with its steep slope and deep and dangerous ravine, the rock is practically inaccessible and forms a part of the fort’s structure. Currently, only ruins of the fort and some towers are apparent, and it is only through archaeological excavation that the main portions can be discovered.

In 1090 CE, Hassan-i Sabbah, the leader of the Assassins, a sect of Nizari Ismailis in Iran, chose the Alamut region as his headquarters to campaign, preach and convert new followers.