Qustion about ruby/sappire

[Pokekid]

While I was walking around I went up to a tree and it said"Vines dropped down, this tree can be climbed" anybody what that means??

[Marril]

You can put your Secret Base there. You need a certain move, though, Secret Power I think.

[Fawkes0126]

You can get Secret Power from a boy standing by a tree a ways above Mauville City.

[Sea Crobat]

With a secret base you can battle other people by mixing records.