Mines on that island to the left of Fallabor, I have:
doll
doll
doll
doll
grass cushion
slide
solid board X2
glass ornament
spikes mat
green poster
and two plants (unsure of names)

Basically its a grass themed secret base, I have always liked secret bases with them.

Mines on route 115, but you have to surf, so u cant walk there. You can catch jigglypuff there too!!



My items: Slide , brakeable door, red balloon, sand ordament, colourful plant, seviper poster, blue balloon, yellow balloon, torchic poster, big plant, blue tent, thunder mat, marril doll, pikachu doll, torchic doll, fire cushion. Total items: 16. The max. I wish nintendo could of put a higher limit, like 20.

Here's my secret base along route 120 where all the clouds float and reflect off the water



I have mostly dolls in it, lol