About the location
When you visit Iceland for the first time and you plan to stay less than 8 days, the southern region of the island is the perfect place to start exploring this amazing country. Most of the popular waterfalls like Seljalandsfoss or Skogafoss are directly located at Route 1, which is the Ring Road around the island. You won't need a 4x4 car here, although I would suggest you one if you want places that are located a little bit more towards the center like the beautiful hills of Landmannalaugar or stunning waterfalls like Haifoss.
Another very popular region in the south is the Golden Circle, which is combining 3 sights as "the Golden Circle Tour". This is probably the most touristic part, but still worth a visit during the right times, since it's not that far away from Reykjavik and still a must-see.