The eastern Algarve has several worthwhile day trips from Tavira. Cacela Velha (12 km east) is a tiny clifftop village with a perfect lagoon view. Castro Marim (30 km east) has a medieval castle overlooking the Guadiana estuary and the Spanish border, plus a salt pan reserve worth visiting for flamingos. Vila Real de Santo António, at the Spanish border, is worth a brief stop for the grid-plan Pombaline town centre and the ferry across the Guadiana to Ayamonte in Spain.
Heading west, Olhão (20 km) has one of the most characterful fishing town centres in the Algarve — the cubist fishermen's quarter and the covered market are both excellent. Faro (30 km) has a well-preserved old town with cathedral and medieval walls, and a bone chapel in the Carmelite church that is one of the more distinctive sights in southern Portugal.