Many people prefer traveling alone -- except for the relatively steep cost of booking a single room, which is usually well over half the price of a double.

Many British agents are keenly aware of the needs of the single traveler. One tour operator whose groups are usually at least half singles is Explore Worldwide Ltd., Nelson House, 55 Victoria Rd., Hampshire, England GU14 7PA (tel. 0870/333-4001; www.explore.co.uk). It has a well-justified reputation for offering offbeat tours, including 14-day expeditions to five islands of the Azores, and motorcoach tours through the highlights of "Unknown Spain and Portugal." Groups rarely include more than 16 participants; children under 14 are not allowed.

TravelChums (tel. 212/787-2621; www.travelchums.com) is an Internet-only travel-companion matching service with elements of an online personals-type site, hosted by the respected New York-based Shaw Guides travel service. They periodically offer trips to Portugal.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.