Children have a special invitation to the world of art this Saturday at the Phillips Collection. Two tours geared to children and entitled "Looking at Landscapes" not only tell about the museum's history, but also bring the Van Goghs, Monets, Hoppers and other paintings to life.

If you miss these tours, you can arrange a private group tour for children through the museum at a later date or take a self-guided tour with a brochure recently published by the gallery for children.

All events are free unless otherwise noted.

NATIONAL ZOO -- Open daily; gates open from 8 to 8; animal buildings, 9 to 6; panda feedings, 11 and 3; elephant training demonstrations, 2; Sea lion training demonstrations, 2, 3001 Connecticut Ave. NW (Rock Creek Park), on the Metro Red Line. Family learning centers Zoolab and Birdlab open Friday through Sunday, noon to 3; Herplab open Wednesday through Sunday, noon to 3. 673-4717.

OXON HILL FARM -- Open daily, 8:30 to 5, Oxon Hill Road (take Beltway exit 3A, turn right on Oxon Hill Road). Friday, 8, "Moonlight Hayride," take a 45-minute ride through Oxon Hill farm by the light of the moon; reservations required. Saturday, 9, "Morning Chores," help a farmer feed the animals, milk the cows and haul the horses to the stable. 839-1177.

NATIONAL AQUARIUM -- Open daily, 9 to 5, Department of Commerce, 14th and Constitution Avenue NW. The sharks are fed Monday, Wednesday and Saturday at 2; weekday features are a touch-tank, mini- theater and a thousand types of marine life. Adults $1; children 50 cents. 377-2825.

CEDAR HILL -- Open daily, 9 to 4, 1411 W St. SE, Anacostia. Cedar Hill, Frederick Douglass' home, recalls his work with films, interpretive exhibits and a house tour. 426- 5961 or 426-5962 or 426-5963.

FRYING PAN FARM PARK -- Open daily, 10 to 6, 2709 West Ox Rd., Herndon. A working model farm with animals such as goats, rabbits and peacocks. Tours for groups of ten or more may be arranged. 437-9101.

USS BARRY -- Open daily, 10 to 5, Washington Navy Yard, Ninth and M streets SE. The Navy destroyer's weather deck is open for public viewing and self-guided tours. 433-3377.

CHILDREN'S MUSEUM -- Monday through Saturday, 10 to 4, Sunday 1 to 4, Rose Hill Children's Museum, north of Frederick. Take U.S. 15 north to Exit 8 to Motter Avenue; follow Motter to left onto 14th Street and left onto North Market Street; follow signs to Rose Hill. Costumed tour guides conduct tours of the 1790 mansion. Hands-on exhibits include a loom and antique toys. Adults $1; under 17 free. 301/694-1646.

DISCOVERY THEATER -- Tuesday through Friday, 10 and 11:30; Saturday, 1 and 3: Arts and Industries Building, 900 Jefferson Dr. SW. "Just So Stories," The Mermaid Theater of Nova Scotia performs Rudyard Kipling's classic children's tales. $2.50, discounts for families and groups. 357-1500.

CAPITAL CHILDREN'S MUSEUM -- Daily, 10 to 5, 800 Third St. NE. Friday, 11, "Nestor the Magician" performs his sleight- of-hand; $2. "Making a Friendship Pin," in the Changing Environment exhibit hall, Saturday and Sunday, 10 to 5. Museum admission $2. 543-8600.

DOLL'S HOUSE AND TOY MUSEUM -- Tuesday through Saturday, 10 to 5; Sunday, noon to 5, 5236 44th St. NW. A collection of antique dollhouses, dolls, toys, games and an exhibit of antique cat games and toys. Adults $2; under 14, $1; group rates available. 244- 0024.

NATIONAL COLONIAL FARM -- Tuesday through Sunday, 10 to 5, 3400 Bryan Point Rd., Accokeek. Sunday, 1 to 4, "Herb Day," find out about gardening, cooking and healing with herbs; also make a sachet. Adults $1; children under 12, free. 301/283-2113.

CLOISTERS CHILDREN'S MUSEUM -- Wednesday through Friday, 10 to 4:30; Saturday, 12 to 4, 10440 Falls Rd., Brooklandville, Maryland. Saturday, 2, "Nature Walk" for children aged five and up with naturalist Jean Worthley; registration necessary. $2 donation requested from adults. 301/823-2551.

RAILROAD STATION MUSEUM -- Wednesday through Saturday, 11 to 4; Sunday, noon to 5, Main Street and Maryland Avenue, Ellicott City. The renovated station has a diorama of the trip of Tom Thumb (an early 19th-century train) from Baltimore to Ellicott City. There are also sight and sound shows, model train exhibits and tours of the museum. Adults $1.25; under 13, 75 cents. 301/461-1944.

COLONIAL FARM -- Wednesday through Sunday, 10 to 4:30, Claude Moore Colonial Farm at Turkey Run, 6310 Old Georgetown Pike, McLean. Take a self-guided tour of farm life for a low-income family in Colonial Virginia. Ongoing demonstrations of agricultural and domestic chores, such as spinning and candlemaking, round out this history lesson. Adults $1; children under 12, 50 cents. 703/442-7557.

ANACOSTIA NEIGHBORHOOD MUSEUM -- Friday 10 to 6; Saturday and Sunday, 1 to 6, 2405 Martin Luther King Jr. Ave. SE. Afro- American history lectures to ages four through eight as well as group tours and teaching services. 287-3369.

YOUTH BALLET -- Friday, 8; Saturday, 3, Fairfax High School, 3500 Old Lee Highway, Fairfax, "Spring Bouquet of Ballet," ballerinas aged 10 to 18 perform to the music of Strauss, Prokofiev, Haydn, Rossini, Verdi. $2; group rates available. 691-2671.

CHILDREN'S THEATER -- Friday, 7:30; Saturday, 3, Robinson Secondary School, 5035 Sideburn Rd., Fairfax, the Assembly Children's Theater presents two comedies, "Onward, Outward, Westward, Upward" and "Our Clever Gretel." 323-8341.

CHILDREN'S RADIO THEATER -- Saturday, 8 a.m., WPFW 89.3 FM. "The Fox Who Laughed Too Much," a story about a clever fox who's undone by his own vanity. Listeners can participate in a call-in following each program by calling 783-3104.

BIRDWALKS ON ROOSEVELT ISLAND -- Saturday and Sunday, 8:30, Roosevelt Island Parking Lot, by the bridge, George Washington Parkway (northbound side only). Bring binoculars, wear subdued clothing and learn what birds look like and how they sound. Reservations required. 285-2598.

BATTING PRACTICE -- Saturday, 10 to 3; Sunday, 1:30 to 4:30; Tuesday and Thursday, 3 to 7:30, Tucker Road Community Park, 1771 Tucker Rd., Fort Washington, Md. Batting cage and automatic pitching machine; bats, balls and helmets provided. $1 for 20 balls; team reservations. 301/248-4404.

SPRING CARNIVAL -- Saturday, 11 to 4, Shepard Elementary School, 14th and Kalmia Road NW. Games, prizes, moon bounce, rummage sale, international foods, arts and crafts. 576-6140.

ART FAIR -- Saturday, 11 to 4, Eaton School, 34th and Macomb streets NW. "34th Street Art Fair," arts and crafts demonstrations, balloon launch, food bazaar, children's art activities. 686-9155.

OLD POST OFFICE -- Saturday, noon to 1, The Pavilion, Old Post Office, 1100 Pennsylvania Ave. NW. Mime Sarah Ewing performs tricks, antics and mime games for kids. 289-4224.

CHILDREN'S MUSEUM TOUR -- Saturday, 1 and 3, The Phillips Collection, 1600 21st St. NW. "Looking at Landscapes," a tour of the Phillips Collection especially for children. Children's tours for groups of 10 or more may be arranged two weeks in advance. 387-2151.

TROLLEY MUSEUM -- Saturday and Sunday, noon to 5, Northwest Branch Regional Park, Bonifant Road between Layhill Road and New Hampshire Avenue, north of Wheaton. Trolley rides: $1, adults; under 18, 75 cents; under two, free. 384-9797.

CHILDREN'S PLANETARIUM -- Saturday and Sunday, 1, Rock Creek Nature Center, 5200 Glover Rd. NW. First show for children four to seven (must be accompanied by an adult); second show for ages seven and up. No latecomers are admitted. 426-6829.

MEET A SNAKE -- Sunday, 7 to 8 p.m., Visitor Center, Huntley Meadows Park, Harrison Lane and Lockheed Bouleard, Hybla Valley (take Beltway Exit 1-S 31/2 miles south to right on Lockheed Boulevard; park entrance three blocks on the left at Harrison Lane). Get a close-up look at a native Virginia snake and learn about its diet and lifestyle. 768-2525.