What are the most worthwhile things to do in Algarve on a first visit?

The central coast's signature sight comes with an instruction manual now. The Benagil cave (Algar de Benagil), a domed sea grotto with a beach inside and a skylight in its roof, 200 yards east of Benagil beach in Lagoa, can since 13 August 2024 be entered only under the Portimão harbor authority's rules (Edital 019/2024): on a licensed boat tour (boats get about two minutes inside, entering by the western arch) or in a guided kayak or paddleboard group of no more than six craft per guide (up to eight minutes, by the eastern entrance). Swimming in and landing on the sand inside are banned for everyone, with fines of up to €2,500 for individuals, and nothing may enter between sunset and sunrise. The famous photos of picnics on that beach are history — plan for a slow pass through on the water, early in the morning before the armada.

The cliffs repay walking more than boating. The Percurso dos Sete Vales Suspensos — the Seven Hanging Valleys trail — runs 3.5 miles (5.7 km) along the cliff tops from Praia da Marinha, one of Europe's most photographed beaches, to Praia de Vale Centeanes, past sinkholes, arches and the fenced skylight of Benagil itself; walk it one way in the morning and bus or taxi back. At Lagos, the Ponta da Piedade headland stacks its arches and grottos at the town's edge, reached by cliff path and a long stairway to the water. End one day at the far southwest: the fortress of Sagres, associated with Henry the Navigator's 15th-century court, and the lighthouse at Cabo de São Vicente, the southwesternmost point of mainland Europe, where the cliffs drop 250 feet (75 m) to the Atlantic.

The east is the coast's other temperament. The Ria Formosa Natural Park, protected since 1987 and covering 44,500 acres (18,000 ha) across some 37 miles (60 km) of lagoon, shelters behind five barrier islands; boats from Faro and Olhão run to Ilha Deserta's emptiness and Ilha da Armona's village lanes, and the lagoon — one of the Seven Natural Wonders of Portugal — holds flamingos, spoonbills, chameleons and what was until recently the world's largest community of two seahorse species. Add a morning in an old town to balance the coast: Tavira, with its Roman bridge and 30-plus churches, or Silves under its Moorish castle, and on a Saturday, Loulé's market hall. If the trip allows one inland hour, drive the Serra de Monchique to Fóia, at 2,959 feet (902 m) the Algarve's highest point, for the whole region in one panorama.

Inside Benagil at 9 a.m. the skylight drops a single column of sun onto the sand you may no longer stand on, and the guided kayaks sit motionless for their eight minutes while the water ticks against the rock.

Most visitors treat the cave boats as the coast's main event and miss that the Seven Hanging Valleys trail passes directly over the cave — you can look down through the skylight for free from the fenced clifftop, then keep walking some of the finest cliff scenery in Europe. The other overlooked giant is the Ria Formosa's seahorse colony: snorkeling and boat guides around Olhão and Faro can show you seahorses in seagrass meadows minutes from the marina, a wildlife encounter most Algarve itineraries never mention.

• Benagil at the first sailing — Book the earliest licensed boat or guided kayak of the day, when the light enters the cave and the water is calmest
• Trail one-way, morning — Walk Praia da Marinha to Vale Centeanes before noon and swim at the beaches on the way
• One day east — Faro's old town, then a boat to a barrier island and a seafood lunch back in Olhão

Swell decides the cave: in rough seas the harbor authority closes cave entries and tours cancel, so never leave Benagil to your last day. The cliff trail has no shade or water along much of its length and the Lagos grotto boats also stop in high wind. Summer weekends jam the small parking areas at Marinha and Benagil; the Ria Formosa island ferries run reduced timetables outside June to September.

Base in Lagos or Carvoeiro, schedule Benagil and the cliff trail into your first two mornings, and give the Ria Formosa a full separate day.