Pokémon HeartGold and SoulSilver/Union Cave

This is a pretty short cave. There are a few things though. There a Geodude, Onix, and Zubat. There are trainers using mostly Rock/Ground types. Some fire type trainers to. Come back here when you Surf and Strength HM's and you'll be able to fully explore it. On Friday's if you surf south to a ladder then go through other stuff you will find a Level 20 Lapras which is the best water and ice types. If you plan to use Lapras not only are you wise, but also patient, because you should go get the HM Surf at Ecruteak city and come back quickly. Also when you go north in the cave you will be able to go to the Ruins of Alph. (You need HM Strength however.)