Downtown Lisbon, known as the **Baixa**, is a grand and orderly grid of elegant streets that rises from the banks of the Tagus River up toward the city's surrounding hills, serving as the commercial and historic heart of the capital. Rebuilt in a remarkably rational, neoclassical style by the Marquis of Pombal following the catastrophic 1755 earthquake and tsunami, it stands as one of the world's earliest examples of earthquake-resistant urban planning. Its wide, pedestrian-friendly streets — most famously Rua Augusta, crowned by its triumphant arch opening onto the vast Praça do Comércio waterfront square — are lined with shops, cafés, mosaic-tiled sidewalks, and grand stone buildings that give the area a stately, almost theatrical feel. The neighboring Chiado district adds a bohemian, literary flair with its bookshops, theaters, and stylish boutiques, while the adjacent Bairro Alto climbs the hillside with narrow streets full of restaurants and bars that come alive at night. Together, these interlocking neighborhoods form a downtown that is simultaneously a living museum of 18th-century urban vision and a bustling, modern city center full of energy and life.