Belém Tower (Torre de Belém) is a 16th-century fortified tower on the Tagus River in Lisbon and a UNESCO World Heritage Site, built to defend the harbor and later used as a ceremonial gateway for explorers departing during the Age of Discovery.
The tower is open Tuesday through Sunday from 9:30 AM to 5:30 PM, with last entry at 5:00 PM; it is closed on Mondays as well as January 1st, Easter Sunday, May 1st, June 13th, and December 25th. Standard adult admission is €15, children under 12 enter free, and the tower is included with the Lisboa Card. Because daily entry is capped at roughly 900 visitors in 30-minute timed slots, booking a specific half-hour window online in advance is strongly recommended, especially in peak season.
Inside, narrow spiral staircases lead up through vaulted chambers to a rooftop terrace with sweeping views over the river and the nearby Monument to the Discoveries.