Dénia's beaches split into two distinct types, divided by the fishing harbour and castle promontory. To the north, Las Marinas is a long stretch of fine sand running for several kilometres, backed by pine trees and low-rise development — wide, flat, and good for families. To the south, Las Rotas is a rockier coast of small coves and natural pools, popular with snorkellers and those who prefer more seclusion. The clear water at Las Rotas is excellent for swimming and underwater exploration.
The town beach closest to the centre (Platja del Raset) gets busy in July and August; the further you go along Las Marinas in either direction, the more space you will find. Cap de Sant Antoni, the headland to the north of town, marks the boundary with a marine reserve where the underwater life is particularly rich.