Biscayne Bay stretches fifteen miles along Miami's eastern edge, a protected estuary where the Atlantic meets the city's downtown grid. The waterway has served as the region's natural harbor since the Tequesta people navigated its channels two thousand years ago, and by the early twentieth century its western shore had become the address of choice for industrialists, entertainers, and shipping magnates. The mansions that line Star Island and the Venetian Causeway today occupy land reclaimed from shallow flats during Miami's 1920s real estate boom. A sunset cruise Miami tour follows a route that reveals the city's architectural evolution in cross-section. Downtown's glass towers rise above Bayside Marketplace, where cruise terminals occupy the site of the old Seaboard Air Line Railway depot. Heading south, vessels pass Fisher Island, accessible only by ferry and home to the highest per-capita income in the United States, and the Art Deco district of South Beach, whose pastel facades glow amber in late-afternoon light. Heading north, the route threads between the mangrove-edged spoil islands and the causeways that connect Miami Beach to the mainland. Star Island's waterfront properties include estates owned by recording artists, professional athletes, and film producers — most built between 1922 and 1940, then renovated with contemporary additions. Biscayne Bay's ecology supports manatees, bottlenose dolphins, and over three hundred bird species. The bay's western mangrove fringe provides nursery habitat for juvenile fish and filters stormwater runoff from the urban watershed. Federal protections established in 1980 created Biscayne National Park at the bay's southern terminus, preserving coral reefs and shipwrecks that date to the eighteenth century. Evening departures time their return to coincide with the illumination of downtown Miami's skyline — the Freedom Tower, Miami Tower, and the newer Brickell financial district creating a tiered wall of light reflected in the bay's calm surface. The thermal stratification of the water column produces the glassy conditions favored by photographers during the golden hour, when horizontal sunlight reduces atmospheric scattering and sharpens color contrast.