Final Fantasy VII/Ancient Forest

Ancient Forest is located on a hill a little bit east of Cosmo Canyon. There are two ways to get there: either breed a green chocobo (or a black or gold one), or defeat Ultimate Weapon, which will clear the path for all vehicles.

Ancient Forest Puzzles
The puzzles here aren't very difficult, as long as you figure out the gist of things before too long. The enemies are annoying, but not impossible if you're strong enough to destroy the Ultima Weapon, which is, of course, the only way to reach the Ancient Forest without doing a whole lot of chocobo breeding. The basis of the puzzles are as follows:

The plant creatures have absurdly high evade scores, but magic usually does the trick; alternatively, you can decide to spend a good deal of time grinding Nanaki or Yuffie until they max out their dexterity.
 * Pressing when facing one of the jumping insects or frogs picks it up.  Pressing  again while holding an insect or frog drops/uses it.
 * You can reset the puzzle at any time by pressing . You can also reset any given screen by leaving the screen and returning.
 * Dropping an insect in front of a hole that emits a frog sound will replace one insect with one frog. This can only be done once per reset.
 * If you drop a frog or insect in front of one of the hanging pitcher plants, the insect or frog is eaten by the plant and you can jump on top of the plant. After a short time, the plant will eat the insect or spit out the frog.
 * If you stand on top of a pitcher plant that has eaten a frog, when the plant spits out the frog, it also sends you flying in a pre-set direction. You can clear some otherwise un-jumpable gaps in this fashion.
 * The giant piranha plants must either be avoided or fed one of the bowling-ball-sized fruits that can be found up high in some screens. They hurt a lot if you step on them. However, if you are very careful, you can swipe the item from inside the first piranha plant without getting eaten. Lightly tap  slowly and you will reach it.
 * The flowers with hanging purple vines will launch you in a preset direction if you can reach them.

Rare items
There are several very nice items in the forest, including the Apocalypse, a triple AP growth sword for Cloud that does very good damage as well. It's possible to get them all with a bit of work.
 * Supershot ST (Vincent's);
 * Spriggan clip (Nanaki's);
 * Slash-All materia;
 * Minerva Band (armor);
 * Typhoon materia;
 * Elixir;
 * Apocalypse sword (Cloud's).