Silver Trench is a dungeon in Pokémon Mystery Dungeon: Red Rescue Team and Blue Rescue Team. You can only access this dungeon after recruiting all the legendary birds, Pitfall Valley and Stormy Sea has been cleared, and after talking to Alakazam and visit the Legendary Island. The Move/HM Dive and a Water Pokemon is required to enter the dungeon. Monster Houses are set to appear at the 15th, 35th, 55th, and 75th floor.