It's easy enough to get to know Boston by following the Freedom Trail on foot. If you prefer to be guided, narrated trips run throughout the day aboard the hundred-minute Old Town Trolley Tours (tel 617/269-7010; $20, $7 kids aged 4-12) or the similarly priced Discover Boston Trolley Tours (tel 617/742-1440, ), which specializes in narrated audio tours in multiple languages. But nothing is as popular (or as novel) as a Boston Duck Tour (adults $22, kids 4-12 $12; tel 617/723-DUCK, ), a very entertaining romp by land and by sea aboard a real WWII amphibious landing vehicle. Same-day tickets are sold inside the Prudential Center daily April through November. Boston By Foot, 77 N Washington St (tel 617/367-2345), conducts ninety-minute walking tours for $8. Also useful are the bus excursions further afield to Lexington, Concord, Salem and Plymouth with Brush Hill Tours/Gray Line (tel 617/720-6342, or ). Boston Bike Tours (tel 617/308-5902, ), on Boston Common, can take you around for a couple of gentle hours by bike. A two-hour tour costs $18, or only $8 if you have your own bike; either way, a helmet, map and water are included.