Pokémon Diamond and Pearl/Wayward Cave

Right Side of Wayward Cave
This is a very large cave, and therefore is easy to get lost in. It is recommended that you get your Pokémon leveled up to mid-30's, because there are lots of wild Pokémon and trainers to fight. Trainers' Pokémon are around level 18-20.

Also, if you get sick of battling wild Pokémon, it is recommended that you bring along about 30 Repels, 15-20 Super Repels, or 10 Max Repels if you plan on visiting the whole cave. Also, you will want a Pokémon that knows Flash, as the cave is dark and it is nearly impossible to get through in the dark. You will also need a Pokémon that knows Rock Smash, as there will be several breakable rocks in your way.

In the northeastern-most corner of the cave you will meet a young lady named Mira and have to escort her back to the entrance. In return, she will heal you after every fight. She may also appear as a partner in the Multi Player part of the Battle Tower. Her one Pokémon in the cave is a level 18 Kadabra.

Items

 * Escape Rope
 * TM32 (Double Team)
 * Rare Candy

Left Side of Wayward Cave (Hidden)
Under the Cycling Road there is a little grotto that is hidden, allowing access to a second and extra side of Wayward Cave.

There are Pokémon, but no trainers. A Pokémon with Strength is needed, along with Flash, and some sort of repellent (Max Repels and a high level Pokémon work best). A bike is needed for most of this "maze". To jump ramps with the bike, you need to have the bike in 4th gear.

Items

 * TM26 (Earthquake)
 * Max Ether
 * Revive
 * Grip Claw