探検
たんけん · tanken · JLPT N1 · noun
exploration
探 — hand radical 扌 + 罙 (depth/cave)
探 combines the hand radical 扌 with 罙, which depicts a hand reaching into a cave or deep place. The original sense was reaching in to feel for or retrieve something hidden, which extended to 'probe,' 'search,' and 'explore.' 罙 also hints at the sound.