Along the south coast of the Caspian this line of elevation is prolonged as the Elburz range(not to be confused with the Elburz of the Caucasus), and has its culminating point in Demavend, which rises to 19,400 ft.
To S.E., the second section of the Elburz begins, and extends from there to beyond Mount Demavend, east of Teheran.
The eastern foot of Demavend is washed by the river Herhaz (called Lar river in its upper course), which there breaks through the Elburz in a S.-N.
(Russian trigonometrical survey), and ending in Khorasan, the great Elburz range presents on its southern, or inward, face a more or less abrupt scarp rising above immense gravel slopes, and reaches in some of its summits a height of nearly 13,000 ft.; and the peak of Demavend, north-west of Teheran, has a height of at least 18,000 ft.
North of Teheran, flows easterly through the Lar plateau, where it is known as the Lar River, and takes up several affluents; turns to the northeast at the foot of Demavend, leaving that mountain to the left, and flows due north past Amol to the Caspian.