Local Monsanto – Idanha – CB
This is the schedule in effect from 12 July 2021.
Train
Nearest station is Castelo Branco. Consult schedule and book tickets on https://www.cp.pt/passageiros/en
(It used to be only journeys that included at least a part on Intercity were bookable online, but not those completely on Regional trains, but this may have changed lately.)
Booking several days in advance typically yields a significant discount.
If you’re booking a train to get to Lisbon airport, get off at Lisboa Oriente and take the Metro (Linha Vermelha), it’s 3 stops to the airport.
Long distance coach
https://www.rede-expressos.pt/en
If you’re booking a coach to get to Lisbon airport: Sete Rios bus terminal is some ways from the airport. Check here for transfer options https://www.rome2rio.com/s/Sete-Rios-Station/Lisbon-Airport-LIS