There's no pretending that The Narrow Boat (119 St. Peters St., N1; tel. 020/7288-0572; MC, V; Tube: Angel) is historically significant. It's simply a smashing place to pass a few hours on a pretty day. Picture windows overlook an attractive basin of the Regent's Canal, where you can watch barges, ducks, and wealthy folks in their waterfront loft conversions. Combine a visit with a stroll along the canal's footpath, and you've got one of the most romantic afternoons London has to offer.