Where in the world are Sepi and Matt?

123456789101112131415161718
Across
  1. 3. NSW town (6)
  2. 4. Tropical island (8)
  3. 6. Onsen town (10)
  4. 8. Red bornhardts (4,5)
  5. 9. North of the north (6)
  6. 10. Don't bring cumin here (6)
  7. 11. Crossing between two parks (6,6)
  8. 13. Alpine hut (8)
  9. 15. Arty land mass (8)
  10. 17. Thousands of temples (5)
  11. 18. Kea, mice, and ridges (6)
Down
  1. 1. Active volcano (10)
  2. 2. Hidden castle (6)
  3. 3. Lost keys (2,6)
  4. 5. Icy retreat (3,7)
  5. 7. Two lost hikers (5,6)
  6. 10. Temple of 90,000 images (3,5)
  7. 12. Wine island (7)
  8. 13. Easterly point (5)
  9. 14. Nonexistent falls (6)
  10. 16. Arakanese capital (5,1)