Terminal observation decks 展望デッキ
Each terminal has a free rooftop deck. Terminal 1 is the JAL side, Terminal 2 the ANA side, and Terminal 3 is international.
Terminal 1 is best from sunrise to noon and is also great at blue hour. Terminals 2 and 3 are better in the afternoon. At night all three are great, and Terminal 1 has the most light.
When it rains, go to Terminal 1: part of the deck has a roof.