The Eastern Palace is your first true dungeon challenge. Located east of Hyrule Castle, it houses the first of the three Pendants of Virtue. Before entering, ensure you have full health and consider renting the Bow from Ravio's Shop, as it will be incredibly useful for solving puzzles and defeating enemies within. The dungeon introduces the concept of merging into walls, a core mechanic of the game, so be prepared to utilize it frequently.
Inside the palace, you'll encounter new enemies like Popos and Armos. The Bow is particularly effective against the Armos statues. The main goal is to navigate through the various rooms, activate switches, and find the Big Key to unlock the boss door. Pay close attention to the wall textures; any wall that looks slightly different or has a distinct pattern is usually a candidate for merging. Don't rush through; take your time to observe your surroundings and plan your movements, especially when dealing with moving platforms and environmental hazards.