A car is not essential but convenient. Local Soya Bus service runs from Oshidomari Port with buses every 2-3 hours during summer (¥310, 5 minutes to Himenuma Iriguchi stop), followed by a 20-minute uphill walk. Organized bus tours, rental cars, or taxis are alternative options. Bringing a rental car on the ferry from Wakkanai is expensive, so consider renting directly on the island.