World 4 (Super Mario 3D World)
From the Super Mario Wiki
World 4 is the fourth world of Super Mario 3D World. It is a canyon and mountain-like island. It contains five standard courses, two Enemy Battles, a Mystery House, a Sprixie House, and a Castle. After beating the boss, Boss Brolder, the orange Sprixie Princess will create a Clear Pipe to World 5.