PORTUGAL // Prepare to be smitten by this World Heritage maze of alleyways, rising up from the Douro River in a helter-skelter of pastel- colored houses, bell towers and exuberantly gilded baroque and Gothic churches. Cobbled lanes twist past pavement cafes and craft shops, delis and tempting little wine bars, while a flight of seemingly never-ending steps leads to the city's crowning glory, the fortress-like Sé cathedral. Down by the river, you can sense the Atlantic as gulls squawk overhead, sardines sizzle and traditional wooden rabelo boats putter by. Here the double-decker arched Ponte de Dom Luís I makes a spectacular leap across the Douro to Vila Nova de Gaia, where historic port-wine lodges offer tastings of prized rubies and tawnies.