Best swimming pool

When it's hot outside, the Colonnade Hotel opens its roof deck, and for $12 you can spend an entire day (weekdays, 10 a.m.-8 p.m.; 10-6 on weekends) splashing around in the pool and looking up at the big blue sky from your deck chair. Get a drink at the full bar, order a bite to eat from the hotel kitchen, and wonder why anyone bothers with the beach at all. Honorable mention goes to the pools run by the Metropolitan District Commission, which has facilities throughout Greater Boston, including Everett, Waltham, Stoneham, Malden, Watertown, Hyde Park, and Chelsea. Although less glamorous than their high-priced counterparts, the MDC pools are open to the public and free to all comers.

For die-hard lap swimmers who don't care a whit about the sun, though, nothing beats the YMCA pools that proliferate in the area. Regularly scheduled adult lap times rotate with family swim times, after-school programs, and swim lessons, making it easy to know what to expect once you get there -- or before you go. And the membership rate, which gives you access to a lot more than the pool, is a bargain. Check out the Cambridge YMCA: its pool, which dates back to World War I, is the oldest in Massachusetts. But at least it doesn't smell that way.

Colonnade Hotel, 120 Huntington Avenue, Boston, (617) 424-7000; Metropolitan District Commission, 20 Somerset Street, Boston, (617) 727-1300; Young Men's Christian Association Central Branch, 316 Huntington Avenue, Boston, (617) 536- 7800.