The Department of Conservation & Recreation, or DCR (tel. 617/626-1250), oversees outdoor activities on public lands across the state through its divisions of Urban Parks & Recreation and State Parks & Recreation. (The Division of Urban Parks & Recreation replaced the Metropolitan District Commission, a name that still appears on many signs.) The incredibly helpful website includes descriptions of properties and activities, and has a planning area to help you make the most of your time.

Beaches

The beaches in Boston proper are not worth the trouble. Besides being bone-chilling, Boston Harbor water is subject to being declared unsafe for swimming. If you want to swim, book a hotel with a pool. If you want the sand-between-your-toes experience, visit the North Shore or Walden Pond in Concord.

Biking

Even expert cyclists who feel comfortable with Boston's layout (a tiny group) will be better off in Cambridge, which has bike lanes, or on the area's many bike paths. State law requires that children under 12 wear helmets. Bicycles are forbidden on buses and the Green Line at all times and during rush hours on the other lines of the subway system.

On summer Sundays from 11am to 7pm, a flat 1 1/2-mile stretch of Memorial Drive in Cambridge, from Western Avenue to the Eliot Bridge (Central Sq. to west Cambridge), closes to cars. It's also popular with pedestrians and in-line skaters, and it can get quite crowded. The Dr. Paul Dudley White Charles River Bike Path is an 18-mile circuit that begins at Science Park (near the Museum of Science) and runs along both sides of the river as far as Watertown. You can enter and exit at many points along the way. Bikers share the path with joggers and in-line skaters, especially in Boston near the Esplanade and in Cambridge near Harvard Square. The DCR maintains this path and the 5-mile Pierre Lallement Bike Path, in Southwest Corridor Park, which starts behind Copley Place and runs through the South End and Roxbury along the route of the MBTA Orange Line to Franklin Park. The 11-mile Minuteman Bikeway starts at Alewife station at the end of the Red Line in Cambridge. It runs through Arlington and Lexington to Bedford along an old railroad bed and is a wonderful way to reach the historic sites in Lexington.

Rental shops require you to show a driver's license or passport and leave a deposit using a major credit card. Back Bay Bicycles offers hourly rentals for around $10 an hour, with a minimum of 2 hours. Daily flat rates start at $25. Check out Back Bay Bicycles, 366 Commonwealth Ave., near Mass. Ave. (tel. 617/247-2336); Boston Bicycle, 842 Beacon St., about 3 blocks from Kenmore Square (tel. 617/236-0752); and Cambridge Bicycle, 259 Mass. Ave. (tel. 617/876-6555), near MIT. For additional information, contact MassBike (tel. 617/542-BIKE).

Golf

You won't get far in the suburbs without seeing a golf course, and given the sport's popularity, you won't be the only one looking. If possible, opt for the lower prices and smaller crowds that you'll find on weekdays. The Massachusetts Golf Association (tel. 800/356-2201 or 774/430-9100) represents more than 400 golf courses around the state. It has a searchable online database and will send you a list of courses on request.

One of the best public courses in the area, Newton Commonwealth Golf Course, 212 Kenrick St., Newton (tel. 617/630-1971), is a challenging 18-hole Donald Ross design. It's 5,305 yards from the blue tees, par is 70, and greens fees are $30 on weekdays and $37 on weekends.

Within the city limits is the legendary 6,009-yard William J. Devine Golf Course, in Franklin Park, Dorchester (tel. 617/265-4084). As a Harvard student, Bobby Jones sharpened his game on the 18-hole, par-70 course, which is managed by the city parks department. Greens fees are $38 on weekdays and $47 on weekends.

Less challenging but with more of a neighborhood feel is the 9-hole, par-35 Fresh Pond Golf Course, 691 Huron Ave., Cambridge (tel. 617/349-6282). The 3,161-yard layout adjoins the Fresh Pond Reservoir, and there's water on four holes. It charges $21, or $31 to go around twice, on weekdays; $25 and $37, respectively, on weekends.

Gyms

If your hotel doesn't have a health club, the concierge or front desk staff can recommend one nearby and possibly give you a pass good for free or discounted admission. Guests at the Ritz-Carlton, Boston Common, have the use of the over-the-top facilities at the 100,000-square-foot Sports Club/LA, which is otherwise closed to nonmembers. Other hotels with good health clubs include the Boston Harbor Hotel, the Four Seasons Hotel, the Hilton Boston Logan Airport, the InterContinental Boston, and the Royal Sonesta Hotel.

The "Y" offers the best combination of facilities and value. The Wang YMCA of Chinatown, 8 Oak St. W., off Washington St. (tel. 617/426-2237), is convenient to downtown; the Central Branch YMCA, 316 Huntington Ave. (tel. 617/536-7800), is near Symphony Hall. A 1-day pass costs $10 and includes the use of the pool, gym, weight room, and fitness center. Fitcorp (tel. 617/375-5600) charges $20 for a guest pass and offers well-equipped facilities but no pool. It has a dozen area branches, including 1 Beacon St., near Government Center (tel. 617/248-9797); 125 Summer St., in the Financial District (tel. 617/261-4855); and 197 Clarendon St. (tel. 617/933-5090) and 800 Boylston St., in the Prudential Center (tel. 617/262-2050), both in the Back Bay. A day pass costs $20 at women-only, no-pool Healthworks, which has well-equipped facilities in the Back Bay at 441 Stuart St. (tel. 617/859-7700) and in Cambridge at the Porter Square Shopping Center, 35 White St. (tel. 617/497-4454).

Hiking

For information about hiking in state parks and forests, visit the Massachusetts Department of Conservation and Recreation website. The Boston Harbor Islands offer great hiking; circling the largest island, Peddocks, takes half a day.

The Bay Circuit Trail & Greenway is a 200-mile corridor of open space that curves around Boston from Newburyport, near the New Hampshire border, to Kingston Bay, north of Plymouth. Some 150 miles are currently open to the public. The ribbon of conservation land touches on 50 cities and towns; it comes closest to the areas covered in this book when it cuts through Concord along the north shore of Walden Pond. For information, contact the nonprofit Bay Circuit Alliance, 3 Railroad St., Andover, MA 01810 (tel. 978/470-1982).

Ice Skating & In-Line Skating

The outdoor ice skating season runs from mid-November to mid-March, weather permitting. Check ahead for open hours and closures for private events.

The rink at the Boston Common Frog Pond (tel. 617/635-2120) is an extremely popular cold-weather destination. It's an open surface with an ice-making system and a clubhouse. Admission is $4 for adults and free for children under 14; skate rental costs $8 for adults, $5 for kids. The rink gets unbelievably crowded on weekend afternoons, so try to go in the morning or on a weekday.

Kendall Square Community Skating, 300 Athenaeum St., East Cambridge (tel. 617/492-0941), is an open rink in a courtyard not far from MIT. It charges $3 for adults, $2 for seniors and students, $1 for children under 11; skate rentals are $5.

Cambridge's Charles Hotel (tel. 617/234-8008) has a small ice rink off the lobby. It's open weekdays from 3 to 8pm, weekends from 10am to 8pm. Admission is $5 for adults, $3 for children under 12; skate rental costs $5.

A favorite spot for in-line skaters is the Esplanade, between the Back Bay and the Charles River. It continues onto the bike path that runs to Watertown and back, but after you leave the Esplanade, the pavement isn't totally smooth, which can lead to mishaps. Your best bet is to wait for a Sunday in the summer, when Memorial Drive [ST] near Harvard Square in Cambridge closes to traffic from 11am to 7pm. It's a perfect surface. Unless you're confident of your ability and your knowledge of Boston traffic, stay off the streets.

To rent skates or blades, visit the Beacon Hill Skate Shop, 135 Charles St. S. (tel. 617/482-7400). It's not on Beacon Hill but near the Theater District, not too far from the Esplanade, and has a knowledgeable staff. Expect to pay about $15 a day. The InLine Club of Boston's website offers up-to-date event and safety information.

Jogging

The Dr. Paul Dudley White Charles River Bike Path is also a jogging route. The 18-mile loop along the water is extremely popular because it's car-free (except at intersections), scenic, and generally safe. The bridges that connect Boston and Cambridge allow for circuits of various lengths. Be careful around abutments, where you can't see far ahead. Don't jog at night, and try not to go alone. Visit the DCR website to view a map that gives distances. If the river's not convenient, the concierge or desk staff at your hotel probably can provide a map with suggested jogging routes. As in any other city, stay out of park areas at night.

Sailing

Sailboats fill the Charles River basin all summer and skim across the Inner Harbor in all but the coldest weather. Your options during a short stay aren't especially cost-effective, but they are fun.

The best deal is with Community Boating, 21 David Mugar Way, on the Esplanade (tel. 617/523-1038). Visitors pay $100 for 2 days of unlimited use in the Charles River Basin, a gorgeous but congested patch of water between the Back Bay and Cambridge's Kendall Square. The oldest public sailing facility in the country offers lessons and boating programs for children and adults from April through November. The fleet includes 13- to 23-foot sailboats as well as Windsurfers and kayaks. The Boston Sailing Center, Lewis Wharf, off Atlantic Avenue (tel. 617/227-4198), offers lessons for sailors of all ability levels. The center is open year-round (even for "frostbite" racing in the winter). The least expensive 30-day mini-membership costs $350.

Tennis

Public courts are available throughout the city at no charge. Well-maintained courts that seldom get busy until after work are at several spots on the Southwest Corridor Park in the South End (there's a nice one near West Newton St.). The courts on Boston Common and in Charlesbank Park, overlooking the river next to the bridge to the Museum of Science, are more crowded during the day. To find the court nearest you, ask the concierge or desk staff at your hotel or visit the DCR website.