How many days in Portugal?

With less time, choose one base and use day trips rather than forcing both Faro and Lagos into very short stays.

Add nights to Faro or Lagos first, then consider Tavira or another Algarve stop only if transport and beach priorities justify another move.

With less time, choose either Lagos or Tavira and use day trips rather than adding a second hotel base.

Add nights to the side of the Algarve that matches your priorities before adding Faro, Sagres, or an inland detour.

If the trip is too short for three bases, keep Porto and Lisbon and visit Coimbra only when the rail timings still leave enough useful time on the ground.

Add nights in Porto, Coimbra, or Lisbon before branching to the Douro, Sintra, or another region that changes the transport pattern.

With less time, remove the Douro if the transfers start to dominate the trip.

Add a night in Porto or Lisbon before inserting another coastline.

With five or six days, keep both cities only if the intercity transfer still leaves at least two useful days in each; otherwise choose one city and its nearby region.

With nine or ten days, add a day trip or one deliberate third stop such as Coimbra, Sintra, or the Douro rather than multiplying short overnight bases.