Lit caves, a free level-up from the Crystal statue, and access to the western-Hyrule preparation loop.
Optional
A 50-point bag waits in the lone forest north of North Palace; palace side rooms also hold point bags and a Fairy.
Missable
Nothing is permanently missable here, but the palace seals after its item is collected and its Crystal is placed.
Numbered 100% route
Leave North Palace and clear the lone forest to the north if you want the early 50-point bag, then follow the southeast road to Rauru.
In Rauru, speak with the woman in purple and enter her house. Meet the Wise Man in the basement to learn Shield; town women can refill life or magic.
Take the cave northeast of Rauru. The cave is still dark, so stay low, watch the ground, and defeat or avoid the Lowder before exiting east.
Follow the coastal route south through the forced action scene. Jump the water gaps and rising bubbles; falling in the water costs a life.
Enter the small grass clearing, defeat the orange Goriya, and collect Heart Container #1. Backtrack through the bubble path and travel northeast across Parapa Desert.
Enter Parapa Palace, descend the first elevator, and go left for the first Key. Return, go right through the locked door, pass the next lift, and use the Fairy at the far end if needed.
Ride the eastern elevator up, collect the upper-floor Keys, and use the descending route beyond the central lift to reach the palace's western lower branch.
Cross the collapsing bridge for the optional point bag, then continue left and claim the Candle. It permanently illuminates caves.
Backtrack to the boss route, preserve enough life for the final rooms, defeat Horsehead, take the dropped Key, and place the first Crystal.
Boss strategy
Cast Shield before committing to close range.
Horsehead's armored body is safe; jump and slash the exposed head, then retreat before the mace swing.
Keep the fight centered so you have room to jump away from the returning mace.