Hi Maithali, Here is a possible 10-12 day itinerary for a trip to Cambodia and Vietnam: Hanoi Vietnam Day 1: Arrive in Hanoi, Vietnam. Day 2: Explore Hanoi, including Ho Chi Minh Mausoleum, the Temple of Literature, and the Old Quarter. Day 3: Take a day trip to Halong Bay, a UNESCO World Heritage Site. Day 4: Fly from Hanoi to Siem Reap, Cambodia. Day 5: Visit Angkor Wat, the largest religious monument in the world. Day 6: Explore the other temples of Angkor Wat, such as Angkor Thom and Ta Prohm. Day 7: Take a boat trip on Tonle Sap Lake, the largest freshwater lake in Southeast Asia. Day 8: Fly from Siem Reap to Ho Chi Minh City, Vietnam. Day 9: Explore Ho Chi Minh City, including the Cu Chi Tunnels and the War Remnants Museum. Day 10: Take a day trip to Mekong Delta, a vast river delta in southern Vietnam. Day 11: Relax on the beach in Nha Trang, Vietnam. Day 12: Fly from Nha Trang to Hanoi and depart for home.