Aravalli mountain range, situated in the central part of Rajasthan, is considered to be the oldest mountain range of the world, which has turned into a residual mountain due to the process of denudation. The total length of this mountain range is 692 km, out of which the length of 550 km is found in Rajasthan.

The Extension of Aravalli Mountain Range: It is extended mainly in the districts of Sirohi, Udaipur, Rajsamand, Ajmer, Jaipur, Dausa, Alwar, Sikar and Jhunjhunu. It is in a series from Sirohi to Khetari, and after that, it is spread up till Delhi in the form of small hills. Divisions of Aravalli: 

It has been divided into three areas:

1. Northern Aravalli 

2. Central or middle Aravalli 

3. Southern Aravalli.

1. Northern Aravalli: It is the northern – most part of Aravalli mountain range which is extended from Jaipur to Khetari. It is mainly extended in the districts of Dausa, Alwar, Sikar, and Jhunjhunu. The hills of Toravati, Shekhawati, Jaipur and Alwar are included in this region of Aravalli. The average height of these hills is from 450 meters to 700 meters. The highest mountain peak of this part is Raghunathgarh (1055 m). 

2. Central or Middle Aravalli: This part of Aravalli is spread from Jaipur to Ajmer. Mountain range of this part of Aravalli is in alternate series. The important peak of this part is Taragarh which is 885 meters high. The river Luni orginates in this part of Aravalli. 

3. Southern Aravalli: This part of Aravalli is extended from Ajmer to Abu. The peaks in this part have the highest height. The highest peak of Aravalli, Guru Shikhar (1722 meters), is situated in this part. Other important peaks are Achalgarh, Delwara, Kumbhalgarh, etc. which are also situated in this part of Aravalli. The plateau of Bhorath lies between Kumbhalgarh. (North Udaipur) and Gogunda which is the origin point of the rivers flowing towards the east.