Here's a selection a ghoulish delights -- from haunted mansions to "Skate and Scream," from Ghastly Disco to a midnight organ recital reminiscent of the Phantom of the Opera. HAUNTED HOUSES MARYLAND ACOKEEK, Blood Manor, Friday, 7:30 to 5 a.m., Saturday, 7:30 to midnight, Sunday to Thursday, 7:30 to 11, through Nov. 9, Route 373 and Indian Head Highway. Admission $3. Call 292-9333. BOWIE Jaycees, Friday and Saturday, 7 to 11, Bowie Free State Mall, on Route 450.Admission $2. Under 12, $1.50. Call 262-2150. COLLEGEPARK Jaycees, Friday and Saturday, 7 to midnight, Hell Hall, 4306 Farragut Street, Hyattsville. Admission $1.75. Call 779-4761 between 5:30 and 7. FOREST HEIGHTS, Monster Mansion, Friday to Sunday, 7 to 11, Municipal Building, 5508 Arapahoe Drive. Admission $1. Call 248-1260. GAITHERSBURG Jaycees, Friday, 7:30 to 11, Lakeforest Mall. Admission $1.25 in advance, $1.75 at the door. One adult free with three or more children under 12. Call 948-3220. LAUREL Jaycees, Friday and Saturday, 6 to 11, Evil Estates, on Montgomery Street between Seventh and Eighth Streets. Adults $2, children $1. Call 596-5683 or 468-4150. POLLESVILLE Jaycees, Friday, 7:30 to midnight, Saturday, 2, Fletchall House, on Route 107 in the center of Poolesville. Admission $1.50. Call 301/349-5274 evenings. PRINCE GEORGE'S COUNTY Jaycees, Friday and Saturday, 7 to 11, Watkins Regional Park in Kettering. Adults $3, children $2.50. Call Frank Lowery, 577-8787. ROCKVILLE Jaycees, Friday and Saturday, 7 to 10:30, Old Montrose Schoolhouse, at Randolph Road and Rockville Pike. Adults $2, children $1.50. Call Dan Heneghan, 986-6900 or 424-5274. UPPER MARLBORO, Creepy Castle, Friday and Saturday, 6 to 10, Queen Anne School, 14111 Oak Grove Road. Admission $2. Call 249-5000. VIRGINIA ARLINGTON, at the Thomas Jefferson Community Center, Saturday, 6 to 10, 3501 South Second Street. Wear old clothes. Admission $1. Call 558-2801. HERNDON Jaycees, Friday, 7 to 11, 310 Spring Street. Adults $2, children $1. Call 476-5266. SPRINGFIELD Jaycees, Friday and Saturday, 7 to 11, School for Contemporary Education, 7201 Wimsatt Road. Admission $2, under 12, $1.50. Call Joe Saunders, 548-1389 day or 941-7704 evenings. GHOULISH GATHERINGS GHOST TRAIN RIDES, Friday, noon to 6, Burke Lake Park, 7315 West Ox Road, Fairfax Station. Take a ride down the haunted trestles. Admission, 40 cents for those not in costume. Call 323-6600. GETTING THE CREEPS, Friday, 2 to 4:30, Museum of Natural History Insect zoo, 10th Street and Constitution Avenue NW. A series of special Halloween lectures on the world of insects. Free. Call 357-1386. TREATS AND MAGIC, Friday, 3 to 5, South Bowie Community Center, 1717 Pittsfield Lane. Magic show, cartoons, costume judging and treats. Free. Call 249-1622. PUMPKIN FESTIVAL, Friday, 3 to 6:30, Watkins Nature Center, 301 Watkins Park Drive, Marlboro. Bring a pumpkin dish with recipe to share. Costume revue, games, songs and pumpkins for sale. Free. Call 249-6202. EXPRESS TRAIN RIDES, Friday, 3 to 7:30, Lake Fairfax Park, 1400 Lake Fairfax Drive. Travel through the haunted woods of the park. Admission 40 cents for those not in costumes. Call 471-5415. CERAMICS WORKSHOP, Friday, 4 to 6, Columbia Park Community Center, 1901 Kent Vilage Drive, Landover. Ceramic witches and kittens. Free. Call 249-9220. FAMILY FEST, Friday, 6 to 8 Children's Center, 1470 Irving Street NW. Goody bags, haunted house, face painting, apple bobbing and prizes. Adults $1, children free. Call 387-6755. MASQUERADE PARTY, Friday, 6 to 8:30, Glassmoor Community Center, 1101 Marcy Avenue, Oxon Hill. DJ spinning records, costume contest, refreshments and treats. For Elementary school age children. Free. Call 567-6033 or 567-6034. GHOSTLY GET-TOGETHER, Friday, 6 to 9, peppermill Community Center, 610 Hill Road, Landover. For pre-school to age 12. Admission $1. Call 336-4497. COSTUME CONTEST, Friday, 6:30, Takoma Park Library Parking Lot, 7500 Maple Avenue. Haunted house and costume parade of pre-school and elementary school age children. Free. Call 270-4048. CREEPY CRUISE, Friday, 6:30 to 9:30, Lake Accotink Park, 5660 Heming Avenue, Springifield. Outwit the ghost of Pirate Pete and change your gold to Halloween treats. Costumes encouraged. Free. Call 569-3464. SPIRITS OF HALLOWEEN, Friday, 7, David Pinn Community Center, 10225 Zion Drive, Fairfax. Costume party for elementary school age through high school. Tricks and treats, movies, games and prizes.Free. Call 830-2417 or 250-9181. SAMANTHA'S CAMPFIRE, Friday, 7, Great Falls Tavern, Maryland. Listen to ghost stories associated with the canal. For ages 6 to 12. Free. Call 299-3613. HAUNTED HUNTLEY MEADOWS, Friday, 7 to 9, Huntely Meadows Park, 6901 South Kings Hwy., Alexandria. A spook walk followed by ghost stories. Free. Call 768-2525. HALLOWEEN HORROR, Friday, 7 to 9, Wakefield Recreation Center, 8100 Braddock Road, Annandale. Halloween carnival, spook walk and costume contest. Free. Call 321-7080.

MORBID MANOR, Friday, 7 to 9, Hunter House at Notoway Park, 9601 Courthouse Road, Vienna. Tours through the haunted mansion, horror movies, contests and treats. Free. Call 938-7532. SKATE AND SCREAM, Friday, 7 to 9, Tucker Road Ice Rink, 1771 Tucker Road, Oxon Hill. Ice skating followed by a horror film. Movie is free for skaters, 50 cents for others. Call 248-4404. ALL HALLOWS EVE, Friday, 7 to 9, Colvin Run Mill Park, 10017 Colvin Run Mill Road, Great Falls, Virginia. The 19th century mill will be filled with ghosts and goblins. Bob for apples and bring a pumpkins to carve. Adults $2, children $1. Call 759-2771. GHASTLY DISCO, Friday, 7 to 9:30, Tucker Road Community Center, 1771 Tucker Road, Oxon Hill. Disco dancing, spook house, costume contest, apple bobbing and refreshments. Admission $1. Children under 6 must be accompanied by an adult. For reservations, call 248-4404. SCIENCE CENTER HALLOWEEN, Friday, 7 to 10, Maryland Science Center, 601 Light Street, Baltimore. Mr. Wizard-type demonstrators, suspense films, costume contest and Halloween novelties. Admission. Call 301/685-2370. BEASTLY BASH, Friday, 7 to 10, Palmer Park Community Center, 7720 Barlowe Road. For ages 3 to 15. Free. Call 773-2220. PARADE OF COSTUMES, Friday, 8 to 10, Benjamin D. Foulois Jr. High, 4601 Beauford Road, Morningside. Costume judging for pre-school and up. Free. Call 248-1260. DISCO DRACULA, Friday, 9 to 1, Glassmoor Community Center, 1101 Marcy Avenue, Oxon Hill. DJ spinning records; dancing and refreshments. Costumes encouraged but not required. For junior and senior high school age. Admission $1. Call 537-6033 or 567-6034. Halloween DANCE, Friday, 9 to 1, Saint Matthews Parish Center, 1814 N Street NW. Costumes are optional but encouraged. Cash bar. Admission $3. Call 828-7663. Costum Ball, Friday, 9 to 2, Potomac Alliance, 1743 Q Street NW. Music, dancing, prizes and cash bar. Admission $2. Call 483-4284.

MASQUERADE DANCE, Friday, 9:30 to 12:30, Market V Gallery, North Carolina Avenue and 7th Street SE. Costume contest, dancing and cash bar. Admission $5. Call 783-5821. PHANTOM OF THE OPERA, Friday, midnight, National Presbyterian Church, 4101 Nebraska Avenue NW. Top off your Halloween party party with some gruesome, ghoulish organ music. HORROR FILMS, Friday and Saturday, 8, Greenbelt Cultural Arts Center, Utopia Theater, 129 Centerway, Greenbelt. "The Phantom of the Opera," "Nosferatu" and "Dr. Faustus." Admission $2. Call 474-7763. HALLOWEEN HAPPINESS, Saturday, 10 to noon, Bladensburg Elementary, 5150 Annapolis Road. Jack-o'-lantern contest, mystery maze and costume judging. For children 12 and under. Free. Call 277-8350. WIZARDS AND WARLOCKS, Saturday, 2, Reston Community Center Theater, Hunters Wood Village Center, Reston. A magical Halloween with Mark Andrew. Admission $1.50. Under 5 free. Call 476-4500. COSTUME PARTY, Saturday, 7:30, First Baptist Church, 16th and O Streets NW. Apple dunking, costume contest, haunted house, games and films. Each game costs 25 cents.