It is set in a valley between two red sandstone cliffs, Peak Hill and Salcombe Hill, through which the little River Sid flows into the English Channel.
There are a number of impressive hotels along the seafront.
The infant Princess Victoria, later to be Queen, was staying in Sidmouth with her parents when her father died in 1819. She remained fond of the town, and this helped to make it fashionable.
Sidmouth is part of the Jurassic Coast, which also includes Lyme Regis. The cliffs along this stretch of coast have yielded many fossils, including those of dinosaurs.
The town has a famous International Folk Festival each Summer.
To the East of the town is a Donkey Sanctuary, and not far away is the Norman Lockyer Observatory.