The Tower of Belém is a historic fortress located in Lisbon, Portugal. Built in the early 16th century, it served as a defense system at the mouth of the Tagus River and as a ceremonial gateway for explorers returning from sea voyages. The tower is a prime example of Manueline architecture, characterized by intricate maritime motifs. Designated a UNESCO World Heritage Site, the tower stands approximately 35 meters tall and features a mix of Gothic and Moorish styles. Visitors can explore its various levels, including a rooftop terrace that offers stunning views of the surrounding area and the nearby Jerónimos Monastery.