Companhia Carris de Ferro de Lisboa operates all transport in Lisbon proper except the metro. Its buses and trams run from about 5am or 6am to about 10pm or 11pm; there are some night bus and tram services.
Pick up a transport map, Rede de Transportes de Lisboa, from tourist offices. The Carris website has timetables and route details.
Don't leave the city without riding popular tram 28 from Largo Martim Moniz or tram 12 from Praça da Figueira through the narrow streets of the Alfama. Go early in the morning or at night to avoid the tourist mobs.
Two other useful lines are tram 15, which runs from Praça da Figueira and Praça do Comércio via Alcântara to Belém, and tram 18 from Praça do Comércio via Alcântara to Ajuda. Tram 15 features space-age articulated trams with on-board machines for buying tickets and passes. Tram stops are marked by a small yellow paragem (stop) sign hanging from a lamp post or from the overhead wires.
You'll pay more for transport if you buy your ticket on board rather than purchasing a prepaid card. On-board one-way prices are €1.80 for buses, €2.85 for trams and €3.60 (return) for funicular rides (one-way tickets not available). Santa Justa, however, costs €5 return.
Viva Viagem card €0.50 from metro-station kiosks (add credit in €5 denominations). Each ride will then deduct €1.40 per trip from the card for buses and metro and €1.80 for suburban Comboios de Portugal trains.
Zapping Allows for pay-as-you-go fares of €1.25 on buses and metro; add credit between €5 and €40 denominations.
Day passes €6 and allows unlimited travel over a 24-hour period on the entire transport network. If you will take more than five trips on the bus or metro on any given day, this is the best and easiest choice.
Lisboa Card Good for most tourist sights as well as bus, tram, funicular and metro travel.
Bilhete Train & Bus Hop-on, hop-off, one-day travel card valid on Comboios de Portugal trains and Scotturb suburban buses between Lisbon, Cascais and Sintra for €15.
The Elevador Baixa and Elevador Castelo are little-known free elevator rides between Baixa and Castelo. The elevators whisk passengers seven stories from inside a Pingo Doce grocery store in Baixa (through the solar-powered Chão do Loureiro parking garage) to one of Castelo's prettiest hilltop lookouts at Zambeze Restaurant on Calçada Marquês de Tancos in Castelo.