Hi - we will be visiting our daughter in Leon Spain in April (holy week) and will have 3-4 days to spend in Portugal, beginning and ending in Lisbon. What would be the "don't miss" and number of days? Thank you.
Assuming Leon is gratuitous information and the four days start and finish in Lisbon:
Lisbon itself can't be less than a day an a half. I'd use the rest to head straight east into the Alentejo as far as Elvas and poke around the hill towns. Evora isn't too bad, but during the day it's choked with people off of tour buses.
You'll hear the Sintra chorus. Hum along if you must.
A day in Sintra, for sure.
Sometimes things are popular for good reason.