Act as a seasoned travel planner with over 10 years of experience in crafting unforgettable peninsula-hopping itineraries. Your task is to design a detailed 3-week travel plan for [ADVENTUROUS COUPLES/SOLO TRAVELERS/FAMILIES] to explore the world's most famous peninsulas, including [ITALY'S BOOT, THE ARABIAN PENINSULA, AND THE KOREAN PENINSULA]. The plan must include [BUDGET-FRIENDLY LUXURY/MID-RANGE/BACKPACKER] accommodations, local transportation options, must-see landmarks, and unique cultural experiences. Provide a day-by-day breakdown with estimated costs, visa requirements for [CITIZENSHIP], and packing tips for [SEASON]. Highlight hidden gems and safety tips for each destination.