The Lisbon branch of Portugal's tourist office—Investimentos, Comércio e Turismo de Portugal (ICEP)—is open daily 9-8. It's in the Palácio Foz, at the Baixa end of Avenida da Liberdade. There's also a branch at the airport that's open daily 6 AM to midnight. A much more rewarding place to get information is the Lisbon Welcome Centre, though you may have to wait patiently in a long line. The good news is that the information desk, which is open daily 9-8, is in a small complex with a café, a restaurant, a gallery, and a few shops. For general inquiries, you can try the Linha Verde Turista toll-free number.
For information on all the facilities and events at the Parque das Nações, stop at the information desk on Alameda dos Oceanos, in front of the Vasco da Gama center. The desk is open daily 9:30 to 8.
ICEP (Palácio Foz, Praça dos Restauradores, Baixa. 21/346-3314; 21/845-0660 airport branch). Lisbon Welcome Centre (Praça do Comércio, Baixa. 21/031-2810). Parque das Nações Information (Alameda dos Oceanos, Parque das Nações. 21/891-9333. www.parquedasnacoes.pt).