Qazvin province is situated in two mountainous and plain areas, it created special geographical conditions that caused the climate variation in this region. This diversity and the existence of a plain has become an important factor for agriculture to be of great importance, so that Iranian archeologists believe that the civilization of agriculture began in Qazvin plain, and later it was transported to the Iranian and eastern plateau, agriculture today is also one way of gaining People's income. Products such as hazelnuts, almonds, raisins, cranberries, grapes, and pistachios are among the most important products that a significant percentage of them are exported.
The province's main vegetation is forests and grassland. Lake Evan is one of the most suitable places for tourism in the summer season, which can be used for fishing and boating. The lake is the largest lake in Qazvin Province, another lake, Shah Sefidkouh, located at Khoshchal Heights. There are many rivers in the plain of Qazvin, rivers such as Shahrood, which were created by merging of the two rivers Almootroud and Taleqanrud. The presence of Qazvin province in the beautiful slopes of the Alborz Mountains has led to the having many high peaks, which see many climbers year-round. Peaks such as Khoshchal, Sialan and Shah Alborz are among the most famous of them.
Other natural attractions are the caves that are the relics of various geological periods in this province, Qal'e Kord Cave, Vali Ghoshnerood cave, Aqajan Cave, Angol ice Cave and Abbas Abad Caves. There are many mineral springs, such as: Sultan Bolagh, Seven Springs of Avaj and others.
As the province is historic and ancient, there are many castles like famous fortress Alamut which is related to the Ismaili era. After the fortresses, the presence of towers is remarkable, which remain the only brick walls of them such as the Tower of Barajin, the large and small tower of Shemiran, the tomb of Kharghan and the tower of Sultan Oveys.
The remains of various historical periods in this province are numerous, the most famous of them are: the old gate of Tehran, the door of the palace, the Sepehdar Garden mansion, the Qazvin grand Hotel, the Qazvin Museum, the Qajar Museum, and the water reservoir of the Grand Mosque. In general, attractions such as Evan Lake, Rudak Basin, Zarabad's Bloody Tree, Soga Valley, Yalagonbad Waterfall, Kuchanan and Andij Valley,Andij Rocks, Qal'e Kord Caves and Alamut and Tomb of Hamdollah Mostofi, should not be avoided in this province.