In 1810, the Duke of Wellington, defending Portugal against Napoleon's army, built a series of forts and earthworks across the peninsula north of Lisbon, from the Atlantic to the Tagus. The Lines of Torres Vedras were so strong that the French, arriving in front of them, simply stopped, and after months of hunger they retreated. Forts and redoubts survive on the hilltops around Torres Vedras, and some have been restored.
This stop lies near Silveira, on the Atlantic coast west of Torres Vedras, where the land drops in cliffs to long sandy beaches. Santa Cruz, the nearest resort, has a beach backed by cliffs and rock stacks, with powerful surf and cold water. It is popular with surfers, and the beaches are lifeguarded in summer.
The Atlantic here is cold, even in August, and the waves can be strong. Swim only in designated areas with lifeguards, and watch for rip currents. On calm days, the rock pools are fun to explore.
Torres Vedras, inland, is a market town with a castle and a famous carnival, one of the liveliest in Portugal. The hills around are covered with vineyards and wind turbines, and the views stretch to the sea.
On the bike, expect a steady crosswind from the ocean and patches of sea fog that roll inland on summer mornings and burn off by noon. Torres Vedras is the reliable place for fuel. Then come back to the coast to eat: sardines in summer, grilled over charcoal, with boiled potatoes and a salad of tomato and onion, cost little and taste of the Atlantic.