Sea Treader's Path border with The Dunes and Sparse Reef is absolutely mint. The spot it right near the trench down to the Lost River and it offers a safe location (if on survival) and borders with the Dead Zone. It's a large flat but land that has heaps of room large rooms and creativity. The edge of the map of course offers a chance to build a viewing tunnel out to view the super sized Ghost Leviathans.
Exact location is right where the start of the large tunnel in the seat treader's path is. To its right coming from the Dunes. The rock faces on either side of it are just sheer drops down to the void except for the area I'm talking about. It's my new favourite location. Above the bridge is the end of the Sparse Reef biome. Follow the End of the Blood Trench into the Sea Treader's path.