My wife and I (mid 30s, enjoy good food and going to bars, as well lively neighborhoods) are flying in and out Lisbon in mid August from the US. We will only take trains. We'd like to spend a half day at beach too. How does this itinerary sound?
Arrive on Sunday morning/Day 1: Lisbon
Day 2: Lisbon
Day 3: Lisbon (day trip to Sintra)
Day 4: Lisbon (Half day to Cascais)
Day 5: Porto
Day 6: Porto
Day 7: Porto
Day 8: Coimbra (it's a Sunday, is that a bad idea?)
Day 9: Take train from Coimbra to Oriente station (flight is at noon)
Another option would be to spend two days in Coimbra at the expense of one day in Lisbon and goto Figiera de Foz. Or we could go straight to Porto and then finish up in Lisbon.
Thoughts?