Alamut Castle is located in the north west of Qazvin Province near Gazorkhan Village. Popularity of this palace is for Hassan-I Sabbah, propagator of Ismailism during Seljuk. After being dumped out of Malik-Shah Seljuk’s palace, he went to Fatimid Caliphe to learn religious principles of Ismailism and was soon called al-Da‘ī al-kabīr. When he returned, he investigated all the places in Iran in search of a seat for his activities and finally selected Alamut area as the place for his activities. There are controversies over the year the castle was built but it can be dated back to the beginning of the Islamic period. Hassan-e Sabbah conquered the castle in 482 hijri year and paid one or three thousand Dinar gold as its price to the expelled king. The castle was occupied by Hulagu Khan in 482 hijri year. Occupying the castle and setting fire to its invaluable library, the castle lost value and turned into a prison and exile. The remains of the castle are very few due to natural and unnatural accidents. The Cultural Heritage Organization of the country is scientifically excavating the area for more information regarding this historical castle. Alamut Castle is called “Hassan Castle” by local people. the castle consists of western and eastern sections. The western side which is higher is called jurghola “meaning upper castle” and pilaghla (meaning great castle). Alamut Castle is one of the most important cultural-historical centers of Iran since the third Hijri century until Safavid era and is registered in the list of national monuments of Iran with number 7252.

In Niaq village, one of Qazvin environs, there is a relatively high rock in which large cavities have been created by natural factors. Inside some of these cavities, there are rectangular ponds carved by the probable residents. These ponds become filled when rain comes. Local residents believe that Muhammad Hanifeh has built a palace upon this porch, but nothing but some pieces of pottery is left from it today. Niaq village is located in the 17 kilometer distance of North of Qazvin and its one of the important grape cultivation centers of the province.

Caravanserai of Sa'd al-Saltaneh was built at the instigation of Sa'd al-Saltaneh (died in 1907 AD), the then Qajar governor of Qazvin. This caravanserai has a very beautiful historical area which is currently the biggest urban caravanserai complex in Qazvin. It was built by Sa'd al-Saltaneh, the then Qazvin governor, during the reign of Naser al-Din Shah. Caravanserai of Sa'd al-Saltaneh is the biggest urban caravanserai is Iran and one of the few Iranian caravanserais that contains several bathrooms, saray, arcade, shotor khan, chahar souq, Rasteh, mosque, tea house and so on. This caravanserai functioned as a trade house. This historical monument was initially registered in the subset of Qazvin bazaar on December 8, 1937. Then it was separately registered under the name the Caravanserai of Sa'd al-Saltaneh and later on August 2, 2005, Sa'dieh Bathroom was separated from the caravanserai under the registration number of 12598.

Aminiha House and Hosseiniyeh is a beautiful luxurious house in Qazvin which was built in the west of Dezej River by Haj Mohammad Reza Amini, one of wealthy merchants of Qazvin. Later, the river was replaced by Molavi Street in Pahlavi dynasty. Aminiha Hosseiniyeh is a shining example of traditional houses. Today, four yards and various parts have remained on the ground floor and in the basement. This house belongs to Haj Mohammad Reza Amini, a reputable merchant, and a part of it was devoted to Hosseiniyeh in 1275 AH (1858 AD). The most beautiful part of the house consists of three halls parallel with each other which are connected through beautiful Orosis. Having nine spans of Orosis and colorful windows, the southern hall is an art masterpiece. The ceiling of the halls is decorated with paintings, mirror work, bowl rackhs , stucco and wooden Girih tiles . There are a crypt, basement, soda shop, etc. under the halls.

Sar dar-e Ali Qapou (transom of Ali Qapou) is one of the historical and touristic relics of Qazvin town, which is located in the beginning of Sepah ST. – the first street of Iran-. This building was one of the seven entrances to the Safavids’ royal Arg. Also, it is the main entrance opening to Shah Street and square, and the door is the only thing left from this set. This building was registered in July 4th, 1934 in the list of Iran’s national relics.

Chehel Sotoun Mansion or Pavilion is one of the important monuments of Safavid period in Qazvin located in the center of Qazvin City, south of Sabzeh Meidan (Azadi Sqaure) in a large garden. It is the only kiosk left from the royal palace complexes of Shah Tahmasp period. This monument was refurbished by Mohammad Bagher Sa'ad Al-Saltaneh, the then governor of Qazvin, in Qajar period and named "Chehel Sotoun". The murals of the first floor are a good example of Qazvin miniature and enjoy worldwide fame. The style of these murals has been inspired by political changes, in a way that the emergence of Nader Shah and Afsharid dynasty can be seen in Chehel Sotoun. Moreover, Qajar emergence can be seen in the third layer of the palace murals which have faded over time. This walls that are decorated with murals are unique, and the existence of three layers of murals demonstrate the passage of different historical periods. Chehel Sotoun Mansion of Qazvin was registered in the list of Iran's historical monuments in 1956 under the registration number of 389. This monument is currently being used as museum of calligraphy.

Darb-e Koushk Gate of Qazvin is one of the oldest gates of Qazvin town which used to be the gate to Alamout, Roudbar, Koushks and northern hunting ground of Qazvin. It has an arch and semicircular shape. Two arcades were built on each side of the corridor that are softly come out and implying an open arms status. This gate has only one view towards the suburban areas, and this view is tiled and Rasmi Bandi is used in it, and the inside looking wall is made of ordinary brick. The tiling of this building was done in the ruling time of Azed Al-Mulk Qajar.

The dual towers of Kharaqan are two brick towers relating to the Seljuq era located in a 29 meter distance from each other and in a one kilometer distance of Hesar village, one of West Kharaqan rural district environs in the Aowj town of Qazvin. Girih tiles and geometrical bricked patterns of Seljuq era is at its climax in this building. Execution of the bricking of these towers indicate the high skills of their constructors and has turned this building to one of the most spectacular buildings of the 5th century A.D. A new method is implemented in the bricking of these buildings which was later used in other buildings such as the Red Dome of Maraqeh as well. The first samples of Nar (Onion and Semi-circular) and detached two layered (hollow) domes can be seen in these towers and this makes it important for its leadership in this field. This relic was registered in June 13th, 1977 in the list of national relics of Iran with the registration number of 1396.

This cave is located in the 20 kilometer distance of the dual towers of Kharaqan, in Hessar village, one of the environs of Abgarm town which is in the coordinates of 48/51/30 eastern longitude and 35/47/54 northern latitude. Its level is approximately 2064 meters higher than the sea level. After passing the entrance of the cave and descending from a 15 meter cross road, a chamber will appear with an area more than 1000 square meters, and has enormously beautiful stalagmites and stalactites. Its origin goes back to the Eligomeous era and to the Cenozoic era.

Cantour Church known as “Bell Tower” was built by Russians in Qazvin during the Second World War when Iran was conquered by Russians. Like other churches, this small church is in cruciform and its altar faces the east. The bell tower is above it with about eleven meters height. The hall includes a praying room and an altar and there are two rectangular sections on its both sides. There are graves of Russians in its yard. The church has a totally different architecture than other buildings in Qazvin due to its irregular polygon, the red brick façade, glazed bricks and decorative geometrical forms.

Jameh Mosque of Qazvin or Atigh Jameh Mosque or the Great Jameh Mosque is one of the greatest mosques in Iran and the oldest jameh mosque in Iran. Its primary building was built on a fire temple from Sassanid era (the fire temple was in the southern porch). The mosque is in a four porch style and is located in Qazvin City. The building was built to the order of Haroun al-Rashid in 192 hijri year. A part of the mosque (including the southern porch) was ruined when Monguls attacked Qazvin and since it was the most important mosque in the city. However, it was repaired in the following period. The monuments of several periods can be seen in this building and after the part from Sassanid era; the oldest part of it dates back to the second Islamic century. The porches were reconstructed in Safavid era. However, the eastern porch was repaired in Qajar period. The mosque was registered in the list of Iran’s national monuments in 1310 with registration number 121.

The holy monument of Shahzadeh Hossein, Imam Reza's son who died in 201 AH, has always been visited by Qazvin pilgrims since the third century AH. As a result, the tomb of many scientists, lecturers, and great men of Qazvin is placed there. Imamzadeh Hossein was Imam Reza's two-year-old son who passed away in 201 AH as a result of a disease and was buried in the southern cemetery of Qazvin City. Except the exquisite wooden shrine, with hollow Girih tiles, that shows the year 806 AH, other remaining monuments belong to Safavid and Qajar dynasties. This place contains a false arch and six minarets each of which has been adorned with beautiful tilework. This monument, originally from Ilkhanid dynasty, was registered in the list of Iran's National Heritage in February 10, 1940 under the registration number of 339.