Before miniature golf, mankind's only uses for black lights were checking clothes for excess lint and warding off shadow puppets. Use light's full potential with today's Groupon: for $9, you get 18 holes of glow-in-the-dark mini golf for two people at Putting Edge's location in Cambridge (up to an $18 value),

Putting Edge's phosphorescent indoor mini-golf course challenges the eyes, ears, and short-game prowess of players of all ages. The 18-hole course confronts club-wielders with twists and turns amid a glowing battleground populated by painted neon trees, glowing statue heads, and iridescent wildlife conservationists. Upbeat music channels players' adrenalin as they expertly navigate their way through the incandescent irrigation routes and prove to competitors that their putting skills, like the bottom of Mazinaw Lake or Celine Dion's hair, are untouchable. Though not included in this Groupon, players may also hone joystick skills and grapple for prizes at Putting Edge's arcade. The glow-in-the-dark atmosphere encourages friendly competition for players of all fitness levels, birthday parties, and group gatherings.