Welcome to "The Great Indoors." Outdoor sports are moving indoors for the winter, allowing once seasonally sidelined athletes to keep fit and stay pumped all the way to spring training.

Your indoor sporting options include swinging for the fences in a batting cage, planting your feet on a rock-climbing wall and splattering friends and family with paint pellets. Indoor sports facilities, unlike most health clubs, are open to walk-ins (for a daily or hourly fee, of course) and rent equipment to newbies who haven't been outfitted yet.

Here are some of the athletics venues where outdoor sports are definitely in:

SPEEDBALL

Paintball Arena 400 Patton Ave., West Babylon 631-694-2707 islandpaintball.net

COST: $25 (plus $10 rental for face mask, goggles and paint gun)

THE LAYOUT: 18,000 square feet of play area with a field covered with indoor turf. Inflatable obstacles stand in for woods.

THE DIFFERENCE: The paint shoots out at slower speeds than the outdoor game (170 mph vs. 200 mph outdoors), yet the indoor version is still called "speedball," says owner John Pennino.

THE RULES: Players younger than 18 must have a guardian sign a waiver every time they play.

ESSENTIAL GEAR: Long-sleeve shirts, long pants (not Sunday best), old sneakers. Or you can rent a jumpsuit for $7.

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ARCHERY

Smith Point Sports 215 E. Main St., Patchogue 631-289-3399 smithpointarchery.com

COST: $25 includes equipment rental; $10 if you bring your own bow and arrows.

THE LAYOUT: 40 indoor archery lanes with multicolored bull's-eye targets.

THE DIFFERENCE: You still score points by landing your arrow as close as you can to the bull's-eye, a la Robin Hood. Since special skills aren't necessary, both beginners and experts are welcome.

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THE RULES: No crossbows.

ESSENTIAL GEAR: Gloves to protect fingers when drawing and releasing the bow string, and an arm guard to shield the inside of your forearm from archery wear and tear.

BASEBALL

Matt Guiliano's Play Like a Pro 1745 Express Dr. N., Hauppauge 631-342-9033 playlikeaprobaseball.com

COST: $2 for 16 pitches

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THE LAYOUT: Four batting cages equipped with pitching machines, which can be set for the height and speed of the pitch. Put in two tokens, swing and try not to whiff.

THE DIFFERENCE: No umps, no outfielders, no outs.

ESSENTIAL GEAR: Bats and helmets (required) are free. You also can bring your own Louisville Slugger.

ROCK CLIMBING

Island Rock 60 Skyline Dr., Plainview 516-822-7625 islandrock.net

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COST: $38.50 for beginner package, including a lesson, harness and show rental, plus a day pass.

THE LAYOUT: A large warehouse building contains 9,000 square feet of climbing area with 100 routes, 30-foot walls and a boulder cave, among other features.

THE DIFFERENCE: No chirping birds, stinging bees or summit scenery.

THE RULES: Just about anyone, including children as young as 6, can climb. But they must work with a belayer, a person on the ground who pays out or takes in the rope as you climb. A trained friend can belay for you, or you can pay a staffer $25 per half-hour.

ESSENTIAL GEAR: Climbing shoes, harnesses and a chalk bag.