Base in Colombo for night 1, then move inland to Kandy for culture and hiking access, continue to Ella for the best adventure day, and finish on the southwest coast near Bentota or Galle for water and beach time before flying out. The key decision is to keep the trip to a tight Colombo–Kandy–Ella–southwest loop by private transfer and train only where it saves time and adds value, because a 5-day Sri Lanka trip is too short for a big zigzag.