Lagoon is a shallow stretch of water partially or completely separated from the sea.
E.g: Chilka lake in Odisha, Pulicat lake in Tamil Nadu and Andhra Pradesh and Vembanad lake in Kerala are the famous lagoons in India

In deserts rocks in the shape of a mushroom, commonly called mushroom rocks.

Cirque, Aretes, U' Shaped Valley

Due to continuous erosion and deposition along the sides of the meander, the ends of the meander loop comes closer and closer. In due course of time the meander loop cuts off from the river and forms a cutoff lake, also called an Ox-bow lake.

Plunge pool is a hollow feature at the base of a waterfall which is formed by cavitation.

Erosion is the wearing away of the landscape by different agents like water, wind, ice and sea waves.

(i) Glaciers erode the landscape by levelling soil and stones to expose the solid rock below.
(ii) Cirque is a glacially eroded rock basin, with a steep side wall and steep head wall, surrounding an armchair-shaped depression.
(iii) As the ice melts, they get filled up the cirque with water and become beautiful lakes in the mountains called as Tarn Lake.
(iv) When two adjacent cirques erode towards each other, the previously rounded landscape is transformed into a narrow rocky, steep - sided ridge called Aretes.

(i) Winds erode the lower section of the rock more than the upper part.
(ii) An isolated residual hill, standing like a pillar with rounded tops are called Inselbergs. E.g. Inselberg in the Kalahari Desert of South Africa.
(iii) When the wind blows, it lifts and transports sand from one place to another. When it stops blowing the sand falls and gets deposited in low hill - like structures. These are called sand dunes. The crescent shaped sand dunes are called Barchans
(iv) When the grains of sand are very fine and light, the wind can carry it over very long distances. When such sand is deposited in large areas, it is called Loess. Large deposits of loess are found in China.

(i) Thenmning water in the river erodes the landscape, which creates a steep-sided valley like the letter 'V' known as 'V' shaped valley.
(ii) Falling of river water over a vertical step in the river bed is called waterfall. lt is formed when the soft rocks are removed by erosion. E.g. Coutrallam falls across the river Chittar in Tamil Nadu.
(iii) Plunge pool is a hollow feature at the base of a waterfall which is formed by cavitation. Alluuvial fan is a deposition of sediment occurs at which the river enters a plain or the foot-hills.
(iv) As the river enters the plain it twists and turns forming large bends known as Meanders. E.g. Meanders along the River Vellar near Sethiyathope in Cuddalore District, Tamil Nadu
(v) Due to continuous erosion and deposition along the sides of the meander, the ends of the meander loop comes closer and closer. In due course of time the meander loop cuts off from the river and forms a cutoff lake, also called an Ox-bow lake.