after beating may or brendon under the cycling road on your way to mauville city
In the grass under Cycling Road (but only if you have Pokemon Emerald inserted in the GBA slot).
Run through the grass under the cycling road in between Mauville, and Slateport City.
On Route 206, under the cycling road. Must find with the poke radar!!
I don't think there is a cave under cycling road in Pokemon heart gold or soul silver, are you sure you have the right name in your question? If you do mean heart gold, the next thing to do after going through cycling road is to go into fuchsia city, beat the gym leader, explore Pal Park, and take route 15, 14, 13, and 12 up to Lavender Town. Good luck!
Gligar is in the grass near cycling road if you insert Pokemon Emerald. In Platinum, the dongle feature is not nessecary.
after beating may or brendon under the cycling road on your way to mauville city
In the grass under Cycling Road (but only if you have Pokemon Emerald inserted in the GBA slot).
Minuns are not rare, you can find them in the tall grass under the cycling road between mauville and slateport.
Go to route 110 above slateport
route 110 between slateport and mauville
cave under cycling road
Nothing
In the grass under Cycling Road (but only if you have Pokemon Emerald inserted in the GBA slot).
you can catch Electrike under the Cycling Road on diamond, pearl, and platinum but on emerald its at the end of Slateport city.Also ondiamond pearl and platinum they are at the giant windmill area.Safari Zone
the cave under cycling road
the cave under cycling road it is Wayard Cave